STUDIES ON THE DIGESTIBILITY OF ORCHARD GRASS

WITH DAIRY CATTLE
I*

A comparison o f seireral tech n iq u es fo r determ ining d i g e s t i b i l ­
i t y c o e f f i c i e n t s w ith d airy c a t t l e .

II.

S tu d ies on th e com position o f l ig n in is o la t e d from orchard
g rass hay c u t a t fou r sta g e s o f m aturity and from th e co rres­
ponding feces*

I I I . A study o f the crude fib e r and n itr o g e n -fr e e e x tr a c t fr a c tio n s
o f orchard g ra ss hay and the d i g e s t i b i l i t y o f some o f th e con­
s t it u e n t s by m ilk in g cows.

by
Ray E* E ly

A THESIS
P resented to th e Graduate School o f Michigan S ta te C ollege o f
A gricu ltu re and Applied S cien ce in p a r t ia l f u lf illm e n t
o f th e requirem ents fo r the degree o f
DOCTOR OF PHILOSOPHY

D airy Department
E ast Lansing, Michigan
1952

ACKNOWLEDGMENTS
The w r ite r w ish es to ex p ress h i s most sin c e r e a p p re c ia tio n
to Dr. C. P. Huffman, Research P ro fe sso r in Dairy Husbandry, and
to Dr. L. A. Moore, Head o f the D iv is io n o f N u tr itio n and P hysi­
o lo g y , Bureau o f D airy In d u stry, B e l t s v i l l e , Maryland, fo r t h e ir
I n sp ir a tio n and coop eration in th e plan ning o f t h i s in v e s t ig a tio n ;
fo r t h e ir advice and c r it ic is m s during th e p rep aration o f t h i s
m anuscript; and fo r p ro v id in g th e n ecessa ry f a c i l i t i e s fo r th e
conduct o f th e se s t u d ie s .

The author lik e w is e w ishes to exp ress

h is a p p re c ia tio n to Mr. E. A. Kane and Mr. W. C. Jacobson,
Chem ists, Bureau o f Dairy In d u stry, fo r t h e ir in t e r e s t and a id
w ith c e r ta in o f th e chem ical a n a ly s e s.

G ratitude i s a ls o ex­

p ressed to Dr. Earl Weaver, Head, Dairy Department, fo r h i s
in t e r e s t and encouragement during th e course o f th e se s t u d ie s .

FORWARD

The r e s u l t s rep orted in t h i s t h e s i s were secured from in v e s t ­
ig a tio n s conduoted over a p eriod o f th e p a st th r ee years#
In order to s im p lify p r e se n ta tio n , th e re s t ilt s have been
d iv id ed in to th ree parts#

p art I was an in v e s t ig a t io n o f se v er a l

d if f e r e n t tech n iq u es fo r determ ining the d i g e s t i b i l i t y c o e f f i c i e n t s
o f forage fo r d airy c a t t l e stu d ied w ith orchard grass hay c u t a t
fou r sta g e s o f m aturity#

P art I I was a study o f th e d i g e s t i b i l i t y

o f lig n in i n orchard grass hays out a t variou s sta g e s o f m atu rity
and an in v e s tig a tio n o f th e com position o f th e lig n in is o la t e d
from th e se orchard grass hays and th e corresponding fec es#

In

P art I I I a more d e t a ile d a n a ly s is was made o f th e crude f ib e r and
n itr o g e n -fr e e e x tr a c t fr a c tio n s and the d i g e s t i b i l i t y o f th e
v a rio u s c o n s titu e n ts rep orted .

STUDIES ON THE DIGESTIBILITY OP ORCHARD
GRASS WITH DAIRY CATTLE

By
Ray E. E ly

AN ABSTRACT
Submitted to the School o f Graduate S tu d ies o f Michigan
S ta te C ollege o f A g ricu ltu re and Applied Scien ce
i n p a r t ia l f u lf illm e n t o f the requireotnents
fo r the degree o f
DOCTOR OF PHILOSOPHY

Dairy Department
1952

Approved

C -

ProQuest Number: 10008233

All rights reserved
INFORM ATION TO ALL USERS
The quality of this reproduction is dependent upon the quality of the copy submitted.
In the unlikely event that the author did not send a com plete m anuscript
and there are missing pages, these will be noted. Also, if material had to be removed,
a note will indicate the deletion.

uest
ProQuest 10008233
Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author.
All rights reserved.
This w ork is protected against unauthorized copying under Title 17, United States Code
Microform Edition © ProQuest LLC.
ProQ uest LLC.
789 East Eisenhower Parkway
P.O. Box 1346
Ann Arbor, Ml 4 8 1 0 6 - 1346

2

STUDIES ON THE DIGESTIBILITY OF ORCHARD GRASS
WITH DAIRY CATTLE
A comparison o f se v e r a l tech n iq u es fo r determ ining d i g e s t i b i l i t y
c o e f f i c i e n t s w ith d a iry c a t t l e was made w ith fou r sta g e s o f orchard
g rass hay fe d to th ree m ilk in g cows*

D i g e s t i b i l i t y c o e f f i c i e n t s c a l­

c u la te d by th e con ven tion al ten day consu m ption-excretion r a t io s were
compared w ith th e c o e f f i c i e n t s c a lc u la te d by th e chromium, lig n in
and p la n t pigm ent r a tio tech n iq u es w ith th e t o t a l c o ll e c t i o n samples
and a ls o w ith p a r t ia l c o lle c t io n s or "grab* samples*
Comparable d ig e s t io n c o e f f i c i e n t s were secured w ith the standard
te n day consum ption-excretion method and th e chromium and p la n t p ig ­
ment r a tio techniques*

D ig e stio n c o e f f i c i e n t s c a lc u la te d by the

crude l ig n i n and th e corrected l ig n i n r a tio tech n iq u es u s in g the
t o t a l f e c a l c o ll e c t i o n samples were both s ig n if i c a n t ly lower than
the d ig e s t io n c o e f f i c i e n t s c a lc u la te d by th e standard consumptione x c r e tio n method.
D i g e s t i b i l i t i e s o f the variou s c o n s titu e n ts in th e fou r sta g e s
o f orchard grass hay o f in c r e a sin g m atu rity were; dry m a tter, 6 9 .0 ,
70*4, 63*9 and 59*4 percen t; p r o te in , 65*7, 60*7, 55*4 and 54*3 p er­
c en t; crude f i b e r , 8 2*5, 78*6, 72*0 and 69.1 p ercen t; and n itr o g e n fr e e e x t r a c t , 6 9 .3 , 74*7, 68.0 and 57.3 p e r c e n t, r e s p e c t iv e ly .
The apparent d ig e s tio n c o e f f i c i e n t s o f lig n in in the orchard
grass hays fe d ranged from 3.8 to 16.0 p e r c e n t.

The l ig n in I s o la te d

from the four sta g e s o f orchard grass o f in c r e a sin g m atu rity had
n itr o g en con ten ts o f 4 .2 5 , 4 .1 5 , 3 .5 3 and 2.41 p e r c e n t.

The average

n itr o g e n co n ten ts o f the lig n in is o la t e d from the corresponding
f e c e s were 5 .1 9 , 4 .1 3 , 3.62 and 2.91 p e rcen t.

5

The benzoic a c id e x c r e tio n in the u rin e per 100 grams o f l ig n i n
fed was lower when feed in g the most mature hay than when fe e d in g th e
other th r e e l e s s mature h ays.

There was no r e la t io n between th e d ig e s ­

tio n c o e f f i c i e n t s o f lig n in and th e urinary e x c r e tio n o f benzoic acid*
The t o t a l raetboxyl con ten t o f th e hay fed was lower than th e t o ­
t a l m ethoxyl con ten t o f th e corresponding f e c e s on a dry m atter b a sis*
The m ethoxyl co n ten ts o f the lig n in is o la t e d from th e v ariou s hays
was h igh er than the m ethoxyl c o n ten ts o f th e lig n in is o la t e d from
the cerresponding fe c es*
D i g e s t i b i l i t y o f the t o t a l m ethosyl co n ten t and the n o n -lig n in
m ethoxyl c o n ten t o f the r a tio n decreased w ith in c r e a sin g m atu rity o f
the orchard grass hay*

D ig e stio n o f th e lig n in methoxyl groups ranged

from 20*3 to 31*6 p ercen t and showed no c o n s is te n t trend in r e la t io n
to th e stage o f m aturity o f th e hay fed*
A more d e ta ile d system o f a n a ly s is th a t in clu ded determ inations
o f th e sta r c h , su g a rs, organic a c id s , p en to sa n s, alpha c e l l u l o s e , and
lig n in on th e orchard grass hays and th e corresponding f e c e s was used
to study the c o n s titu e n ts o f th e crude f ib e r and n itr o g e n -fr e e e x tr a c t
fr a c tio n s*
This system o f a n a ly s is accounted fo r a greater percentage o f the
dry m atter o f th e immature orchard grass hay than w ith th e more mature
orchard grass hay.

Higher percen tages o f th e dry m atter were a ls o de­

term ined in the f e c e s o f anim als fed the immature orchard grass hay
than in the fe c e s o f anim als fed the mature orchard grass hay.

Con­

sid e r a b ly higher p ercen tages o f the t o t a l dry m atter o f fe c e s were
determ ined by t h i s system o f a n a ly s is than were determ ined w ith th e
same a n a ly tic a l tech n iq u es on the forage fe d th ese anim als.

TABLE OF CONTENTS

PART I .
A COMPARISON OF SEVERAL TECHNIQUES FOR DETERMINING DIGESTIBILITY
COEFFICIENTS WITH DAIRY CATTLE.
INTRODUCTION

1

REVIEW OF LITERATURE

3

DIGESTION TRIAL TECHNIQUES
T otal F ec a l C o lle c tio n Technique
Chromic Oxide R atio Technique
L ign in R atio Technique
I n d ig e s tib le P r o te in Ratio Technique
Iron R atio Technique
S i l i c a R atio Technique
P lan t Pigment R atio Technique
Other D ig e stio n T r ia l Techniques
FACTORS AFFECTING THE DIGESTIBILITY OF ROUGHAGES
E f f e c t o f Crude F ib er on D i g e s t i b i l i t y
E f f e c t o f C e llu lo s e Content on D i g e s t i b i l i t y
E f f e c t o f L ignin Content on D i g e s t i b i l i t y
E ffe c t o f Methoxyl Content o f P la n ts on D i g e s t i b i l i t y
E ffe c t o f Stage o f M aturity on D i g e s t i b i l i t y
E ffe c t o f P lan t Ash on D i g e s t i b i l i t y
A s s o c ia tiv e E f fe c t o f Feeds and D i g e s t i b i l i t y
E ffe c t o f A n t ib io tic s on D i g e s t i b i l i t y

3
3
4
9
14
15
17
18
21
23
23
32
36
39
41
45
47
50

SUMMARY OF THE REVIEW OF LITERATURE

53

PLAN OF EXPERIMENT AND METHODS USED

54

EXPERIMENTAL RESULTS AND DISCUSSION

61

SUMMARY

65

LITERATURE CITED

67

PART I I

STUDIES ON THE COMPOSITION OF LIGNIN ISOLATED FROM ORCHARD GRASS
HAY CUT AT FOUR STAGES OF MATURITY AND FROM THE CORRESPONDING FECES.
INTRODUCTION

97

EXPERIMENTAL PROCEDURE

99

RESULTS AND DISCUSSION

100

SUMMARY

104

LITERATURE CITED

106

TABLES

110

PART I I I
A STUDY OF THE CRUDE FIBER AND NITROGEN-FREE EXTRACT FRACTIONS OF
ORCHARD GRASS HAY AND THE DIGESTIBILITY OF SOME OF THE CONSTITUENTS
BY MILKING COWS.
INTRODUCTION

116

EXPERIMENTAL PROCEDURE

120

RESULTS AND DISCUSSION

121

SUMMARY

126

TABLES

133

PART I

A COMPARISON OF SEVERAL TECHNIQUES FOR DETERMINING
DIGESTIBILITY COEFFICIENTS WITH DAIRY CATTLE

INTRODUCTION
One o f t h e m o s t common m e t h o d s u s e d t o e v a l u a t e t h e n u t r i t i v e v a l u e
o f f e e d s i s t o d e te rm in e t h e i r d i g e s t i b l e n u t r i e n t c o n te n t*
o f th e

av e ra g e p ro x im a te co m p o sitio n *

C o m p ila tio n

average d ig e s tio n c o e f f i c ie n t s *

and a v e r a g e t o t a l d i g e s t i b l e n u t r i e n t c o n t e n t v a l u e s f o r a l a r g e n u m b e r
o f f e e d s h a v e b e e n m ade b y M o r r i s o n ( 1 2 6 )

an d S c h n e i d e r

(1 6 1 ).

T ih ile

t h e s e a v e r a g e v a l u e s a r e i n m any i n s t a n c e s d e r i v e d f r o m a l a r g e n u m b e r
of tria ls*

many a r e o f n e c e s s i t y t a k e n f r o m a l i m i t e d n u m b e r o f t r i a l s

an d p e r h a p s f o r a s i n g l e

s p e c ie s.

Many r e s e a r c h -w o rk e rs n e e d t o know t h e

d i g e s t i b l e n u t r i e n t c o n te n t o f a g iv e n fe e d f o r

s p e c i f i c a n im a ls u n d e r

c e r t a i n c o n tr o lle d c o n d itio n s o r u n d er w id e ly v a ry in g c o n d itio n s .
e x a m p le * i t

i s d e s i r a b l e t o know t h e n u t r i t i v e v a l u e o f v a r i o u s p a s t u r e

m ix tu re s under w id e ly v a ry in g c o n d itio n s o f r a i n f a l l ,
ty p e s*

For

s o i l tre a tm e n ts *

te m p e ra tu re *

and g r a z i n g m a n ag em e n t w i t h d i f f e r e n t a n i m a l s

w h ic h v a r y q u i t e w i d e l y i n t h e i r n u t r i t i v e

re q u ire m e n t.

(165) a n a ly z e d th e p u b lis h e d d a t a f o r f i v e

c la s s e s o f fe e d s fed to

s p e c ie s o f a n im a ls to

S ch n eid er e t a l .

T hey c o n ­

c lu d e d t h a t th e p r a c t i c e o f a p p ly in g av erag e d i g e s t i o n c o e f f i c i e n t s
g iv e n f e e d to p a r t i c u l a r

fo r a

sam p les o f t h a t f e e d i s w a r r a n te d d e s p i t e t h e

f a c t th a t a h ig h w ith in -fe e d v a r i a b i l i t y in d i g e s t i b i l i t y

occurs.

stu d ie d p u b lish e d d i g e s t i b i l i t y d a ta to

t h e r e l a t i v e m a g n itu d e o f c e r t a i n

sources o f v a r ia tio n .

25 t o 4 5 p e r c e n t o f t h e w i t h i n - f e e d v a r i a n c e

20 t o

S ch n eid er

d e te rm in e

They f o u n d t h a t

in d i g e s t i b i l i t y I s a s s o ­

c i a t e d w ith v a r i a t i o n s i n p r o x im a te c o m p o sitio n *
c ia te d w ith a u th o rs ,

fo u r

d e te rm in e th e v a lu e o f av era g e d i g e s t i b i l i t y d a t a

In d e te rm in in g th e n u t r i t i v e v a lu e o f p a r t i c u l a r fe e d sam p les.

an d L u c a s ( 1 6 3 ) a l s o

so il

20 t o

40 p e r c e n t o .sso -

35 p e r c e n t a s s o c i a t e d w i t h s a m p l e s o f f e e d

2

and 10 "to 25 p e r c e n t a s s o c i a t e d w i t h t h e t r i a l .
average d ig e s tio n c o e f f i c i e n t s
p o s i t i o n o f th e p a r t i c u l a r

They p o i n t e d o u t t h a t

s h o u l d he a d j u s t e d f o r t h e p r o x i m a t e

s a m p le b e i n g u s e d .

T hey a l s o

com­

su g g e ste d t h a t

a g r e a t e r am ou nt o f t h e v a r i a n c e c o u l d be r e l a t e d t o c o m p o s i t i o n o f t h e
feed i f

o th e r n u tr ie n ts ,

i n a d d i t i o n to th o s e d e te rm in e d in th e u s u a l

p ro x im a te a n a l y s i s , w ere a s c e r t a i n e d .
I n te r e s t in th e

s o -c a lle d i n e r t m a te r ia l " r a ti o te c h n iq u e s " o f

d e te rm in in g th e d i g e s t i b i l i t y o f th e v a r io u s c o n s t i t u e n t s o f fe e d h as
b e e n s t i m u l a t e d l a r g e l y by t h e f a c t t h a t i t w i l l p e r m i t d i g e s t i o n t r i a l
s t u d i e s t o be made u n d e r t h e same c o n d i t i o n s a n d w i t h t h e
t h a t w o u ld n o r m a l l y be u s e d f o r t h e f e e d i n v e s t i g a t e d .
a d d i t i o n o f an i n e r t m a t e r i a l to th e d a i l y

same a n i m a l s

F u rth e rm o re ,

r a t i o n o f a g ra z in g an im al

w o u ld p e r m i t c a l c u l a t i o n o f t h e d a i l y d r y m a t t e r e x c r e t i o n f r o m wg r a b H
sam p les c o l l e c t e d a t c o n v e n ie n t i n t e r v a l s .

The d e t e r m i n a t i o n o f t h e

c o n c e n tra tio n o f an i n e r t n a tu r a lly - o c c u r r in g

c o n s t i t u e n t of th e fe e d

o n b o t h t h e f e e d a n d f e c e s s a m p l e s w o u ld n e r m i t a c a l c u l a t i o n o f t h e
d r y m a t t e r i n t a k e o f t h e a n i m a l s t u d i e d and c a l c u l a t i o n o f t h e d r y
m a t t e r d i gc s t i h i 1 i t y •
The u s e o f t h e

in e r t m a te ria l ra tio

te c h n iq u e fo r d e te rm in in g th e

d i g e s t i b i l i t y o f a f e e d o r r a t i o n w o u ld f a c i l i t a t e
fe e d s w ith d i f f e r e n t

s p e c ie s and under w id e ly v a ry in g c o n d itio n s

are n o t r e a d ily f e a s i b l e w ith th e
te c h n iq u e ,
m e th o d s.

s tu d ie s of v a rio u s
th a t

c o n v e n tio n a l t o t a l f e c a l c o l l e c t i o n

i f d i r e c t c o m p a r i s o n s c o u l d be e s t a b l i s h e d b e t w e e n t h e s e

REVIEW OF LITERATURE
DIGESTION TRIAL TECHNIQUES
T o t a l F e c a l C o l l e c t i o n T ec h n iq u e
D ig e stio n t r i a l te c h n iq u e s in v o lv in g th e t o t a l c o lle c tio n o f fe c e s
o v e r a s p e c i f i e d p e r i o d o f tim e w h ile t h e a n im a ls a r e on a c o n s t a n t f e e d
i n t a k e and c a l c u l a t i o n o f th e d i g e s t i b i l i t y o f th e v a r i o u s n u t r i e n t s fro m
th e n u tr ie n t in ta k e -e x c ro tio n r a t i o n

have changed b u t l i t t l e

sin c e t h e i r

a d o p t i o n b y H e n n e b e r g a n d S to h m a n n ( 9 1 ) .
The l e n g t h o f t h e

c o l le c tio n p e rio d

in d ig e s tio n t r i a l s

u sin g t o t a l

f e c a l c o lle c tio n s fo r se c u rin g s a ti s f a c t o r y d i g e s t i b i l i t y c o e f f i c i e n t s i s
s t i l l a c o n tro v e rs ia l su b je c t.

R e l a t i v e l y few c o m p a riso n s o f th e

o f d i f f e r e n t l e n g t h s o f t r i a l s have b e e n m ade.
Kamml&de ( d 6 ) u s e d c o l l e c t i o n p e r i o d s o f f i v e o r
t h e y w ere t o o

short fo r

H a m ilto n , M i t c h e l l and
s i x days and s t a t e d t h a t

a c c u ra te r e s u l t s w ith ste e rs*

S c h n e i d e r an d

E l l e n b e r g e r ( 1 6 2 ) made a s t u d y o f t h e l e n g t h o f s d i g e s t i o n t r i a l
apparent d i g e s t i b i l i t y .

accuracy

on

They u s e d a t l e a s t a w eek n r e l i m i n a r y p e r i o d an d

r a t i o n s t h a t w o re n e a r m a i n t e n a n c e l e v e l c o m p a re d w i t h h i g h e r l e v e l s o f
n u tritio n .

They f o u n d t h e g r e a t e s t e r r o r i n c a l c u l a t i n g t h e d i g e s t i o n

c o e f f i c i e n t s w as t h e i r r e g u l a r i t y

i n t h e q u a n t i t y o f f o c o s e x c r e t e d w h ic h

was more- p r o n o u n c e d a t lovr n u t r i t i o n a l

(m a in te n a n c e }

le v e ls .

T h ey f o u n d

th e d i g e s t i o n c o e f f i c i e n t s from a n in e -d a y l a c t a t i o n t r i a l

(h ig h p la n e o f

n u tritio n )

from a tw e n ty -

gave a p p r o x i m a t e l y t h e

f o u r - d a y m a in te n a n c e t r i a l ,

H a m i l t o n , M i t c h e l l , K ic k end Garmon ( 3 7 ) u s e d

a te n -d a y c o lle c tio n p e rio d fo r
fo r

same a c c u r a c y a s r e s u l t s

s h e e p and a f o u r t e e n - d a y

c o lle c tio n p e rio d

s t e e r s p re c e d e d by s e v e r a l w eeks o f p r e l i m i n a r y f e e d i n g .

G o to la (1 7 °;

u s e d t e n - d a y c o l l e c t i o n p e r i o d s p r e c e d e d by t e n - d a y p r c l i m i n a r y p e r i o d g
w i t h shee-p o n a l f a l f a

hay.

F o u r t e o n - d a y r> ro lim in e ry p e r i o d s and f o u r t e m

4

d a y c o l l e c t i o n p e r i o d s w e r e u s e d b y M umford e t a l .
t r i a l s w ith s te e r s .

(127) i n d i g e s t i o n

K n i g h t , H e p n e r and M o r to n ( 1 0 5 ) u s e d s e v e n - a n d

e i g h t - d a y p r e l i m i n a r y p e r i o d s and f i v e - d a y c o l l e c t i o n p e r i o d s w i t h
w e th e rs.

These t r i a l s

do n o t g i v e much i n f o r m a t i o n o n t h e

re la tiv e

cu rac y o f d i f f e r e n t le n g th s o f c o lle c tio n ^ p e r io d s sin c e th e t r i a l s

ac­
are

n o t d i r e c t l y co m p a ra b le .
S t a p l e s an d D i n u s s o n ( 1 7 4 ) h a v e r e c e n t l y r e p o r t e d o n t h e r e l a t i v e
a c c u ra c y o f sev en - and te n - d a y c o l l e c t i o n p e r i o d s i n d i g e s t i b i l i t y
w ith s te e r s .

tria ls

They c a l c u l a t e d c o e f f i c i e n t s o f a p p a r e n t d i g e s t i b i l i t y w i t h

t h e d a t a s e c u r e d f r o m s e v e n - and t e n - d a y c o l l e c t i o n p e r i o d s w i t h 27 i n ­
d iv id u a l t r i a l s .

The d e g r e e o f a c c u r a c y s e c u r e d w i t h a s e v e n - d a y c o l l e c ­

t i o n p e r i o d may be s u f f i c i e n t f o r m any s t u d i e s o f a p p a r e n t d i g e s t i b i l i t y
s i n c e t h e y r e p o r t e d t h a t ’•W ith a p o s s i b l e e x c e p t i o n i n t h e c a s e o f
n it r o g e n - f r e e e x t r a c t th e

seven-day c o l l e c t i o n p e rio d

gave c o e f f i c i e n t s

c o m p a ra b le i n a c c u ra c y t o th e t e n - d a y c o l l e c t i o n p e r i o d " .
C h ro m ic O x id e R a t i o T e c h n iq u e
S e v e r a l s t u d i e s h a v e b e e n made w i t h d i f f e r e n t s p e c i e s o f a n i m a l s o n
t h e a d d i t i o n o f know n a m o u n ts o f c h r o m i c o x i d e t o t h e r a t i o n a n d d e t e r ­
m in in g th e c o n c e n t r a t i o n o f ch ro m ic o x id e i n th e r e s u l t i n g f e c e s t o a llo w
th is m a te ria l to

se rv e a s an in d e x o f d i g e s t i b i l i t y .

The u s e o f c h r o m i c

o x i d e a s a n i n e r t t r a c e r s u b s t a n c e w as f i r s t p r o p o s e d b y E d i n ( 5 9 ) who
f e d c h ro m iu m o x i d e i m p r e g n a t e d i n b l o t t e r p a p e r an d r e p o r t e d r e c o v e r i e s
o f 9 9 .1 p e rc e n t w ith s l i g h t v a r i a t i o n in

26 e x p e r i m e n t s .

A b r ie f d e sc rip ­

t i o n o f E d i n ' s c h r o m i c o x i d e i n d i c a t o r t e c h n i q u e w as p u b l i s h e d i n E n g l i s h
by E d i n , K i h l e n a n d l l o r d f e l d t ( 6 1 ) .

T h is r e p o r t g i v e s r a t h e r c o m p le te

d i s c u s s i o n s o f t h e p r e p a r a t i o n o f th e chrom ic o x id e m a c a r o n i, m ix in g o f
feed ,

c o l l e c t i o n o f f e c e s a n d t h e d e t e r m i n a t i o n o f ch ro m iu m o x i d e i n

f e e d s and f e c e s .

5

H a m i l t o n , M i t c h e l l , K i c k and Garm an ( 8 7 ) f o u n d g o o d a g r e e m e n t b e ­
t w e e n t h e c h r o m i c o x i d e r a t i o m e th o d an d t h e t o t a l f e c a l c o l l e c t i o n
m e th o d w i t h s h e e p , p r o v i d e d t h e c o l l e c t i o n p e r i o d s w e r e o f t h r e e d a y s
or lo n g e r i n d u r a tio n .
S a t i s f a c t o r y r e s u l t s w i t h t h e ch ro m ic o x id e r a t i o

te c h n iq u e have

b e e n r e p o r t e d m o r e r e c e n t l y b y A n d e r s e n ( l ) , A n d e r s e n an d F r e d e r i l c s e n
(2 ),

a n d S k u lm o w s k i, S z y m a n s k i a n d 'ifl/yszynski ( 1 6 6 ) u s i n g

sheep and h o r s e s ;

b y B a r n i c o a t ( 1 9 ) a n d L l o y d ( 1 1 2 ) -w ith s w i n e ; b y O l s s o n , K i h l e n a n d C a g e l l
( 1 4 2 ) w i t h h o r s e s ; b y K a n e , J a c o b s o n a n d Moore ( 1 0 2 , 1 0 3 ) w i t h c o w s ; b y
S c h u r c h , L l o y d a n d C r a m p to n ( 1 6 7 ) w i t h r a t s ;

b y I r w i n a n d C ra m p to n ( 9 6 ) ,

K r e u la ( 1 0 8 ) , and V i r t a n e n (1 8 1 ) w ith hum ans; b y C handa e t a l .
g o ats;

(37) w ith

an d b y A x e l s s o n a n d E r i k s s o n w i t h r u m i n a n t s ( 1 5 ) .

B a r n i c o a t ( 1 9 ) o b ta in e d c o n s i s t e n t l y lo w d i g e s t i o n c o e f f i c i e n t s w i t h
s h e e p a n d c a l v e s w hen t h e c h r o m i c o x i d e w as g i v e n i n a g e l a t i n c a p s u l e .
T hey c h e c k e d t h e p o s s i b i l i t y o f r e t e n t i o n o f c h r o m i c o x i d e i n t h e d i g e s ­
t i v e t r a c t an d r e p o r t e d i n c r e a s e d c o n c e n t r a t i o n s i n t h e

sto m a ch f o l d s o f

a lamb*
K a n e , J a c o b s o n and M oore ( 1 0 3 ) made a d i r e c t c o m p a r i s o n o f t h e d i ­
g e s t i b i l i t y c o e f f i c i e n t s o b t a i n e d by u s i n g ch ro m ic o x id e a s an i n d i c a t o r
w i t h t h e t o t a l f e c a l c o l l e c t i o n te c h n iq u e on sam p les r e p r e s e n t i n g t h e
t o t a l c o l l e c t i o n o f f e c e s fro m cow s.

T h i s w as d o n e t o e v a l u a t e t h e

in ­

d i c a t o r m e th o d a n d t o be a b l e t o e l i m i n a t e t h e e r r o r s d u e t o s a m p l i n g
w h ile

s t u d y i n g t h e e r r o r s du e t o t h e m e th o d s b e i n g c o m p a r e d .

of th e ir

in v e stig a tio n

showed t h a t t h e r e w e r e

110

The r e s u l t s

s ig n ific a n t d iffe re n c e s

b etw een th e d i g e s t i o n c o e f f i c i e n t s o b ta in e d by th e t o t a l c o l l e c t i o n
m e th o d an d t h o s e

s e c u r e d by th e

chrom ic o x id e r a t i o p r o c e d u r e .

o f c h r o m i c o x i d e w e r e r e m a r k a b l y c l o s e t o 100 p e r c e n t .

R e c o v e rie s

6

They fe d th e

c h ro m iu m o x i d e a s a 15 p e r c e n t m i x t u r e w i t h "wheat f l o u r

b a k e d i n t o a h a r d b r e a d "which w as d r i e d , g r o u n d i n a W i l e y M i l l a n d th e n ,
m ix ed w i t h t h e

g r a i n i n s u c h a m o u n ts t h a t t h e cow s r e c e i v e d a p p r o x i m a t e l y

15 g ram s o f c h r o m i c o x i d e d a i l y o r 1 0 0 g ra m s o f t h e c h ro m iu m b r e a d m ix e d
w ith th e d a i l y g r a in r a t i o n .
C o m p a r i s o n s o f v a r i o u s m e th o d s o f f e e d i n g may s e r v e t o e m p h a s i z e
t h e i m p o r t a n c e o f t h i s p h a s e o f t h e ’’R a t i o ” p r o c e d u r e s p a r t i c u l a r l y w i t h
t h e u s e o f ch ro m ic o x id e .
V a r i a b l e r e c o v e r i e s o f c h r o m i c o x i d e f r o m s h e e p -were s e c u r e d b y
C r a m p to n a n d L l o y d ( 4 5 ) w i t h d i f f e r e n t m e t h o d s o f a d m i n i s t r a t i o n o f t h e
c h r o m i c o x i d e , b u t t h e i r r e s u l t s i n d i c a t e d t h a t t h e c h r o m i c o x i d e may be
a c c u r a t e l y u sed i n d e te rm in in g th e d i g e s t i b i l i t y o f a sheep r a t i o n , p ro ­
v id e d th e

c h r o m i c o x i d e c a n b e p r e m i x e d w i t h g ro u n d g r a i n i n t h e r a t i o n ,

b u t n o t w h en i t
ro u g h ag e r a t i o n .

is

g i v e n s e p a r a t e l y a s w as n e c e s s a r y o n a n e n t i r e l y
T h is i s

shown i n t h e f o l l o w i n g t a b l e f r o m C r a m p to n a n d

L lo y d ( 4 5 ) w here t h e ch ro m ic o x id e o n t h e ro u g h a g e a l o n e r a t i o n w as f e d
a s a c o n c e n t r a t e d p e l l e t ( s h e e p la n d 2) and on t h e ro u g h a g e p l u s g r a i n
r a tio n th e

c h r o m i c o x i d e w as m i x e d w i t h t h e

g r a i n (s h e e p 5 and 4 ) .

T ab le 1
R e c o v e r y o f C h r o m ic Oxide"*'
Sheep

R a tio n

R e c o v e ry (%)

1

R o u g h ag e + ch ro m iu m p e l l e t s

85

2

R o u g h a g e + c h ro m iu m p e l l e t s

87

3

R o u g h a g e + g r a i n + c h ro m iu m

98

4

R o u g h a g e + g r a i n + ch ro m iu m

99

^■From C ra m p to n a n d L lo y d ( 4 5 ) .

7

T h i s may p a r t i a l l y e x p l a i n t h e lo w d i g e s t i b i l i t y c o e f f i c i e n t s o b t a i n e d
b y B a r n i c o a t ( 1 9 ) w i t h s h e e p and c a l v e s w hen t h e c h r o m i c o x i d e w as g i v e n i n
a g e l a t i n c a p s u l e w h i c h w o u ld be c o m p a r a b l e t o t h e p e l l e t e d
c o n c e n t r a t e f e e d i n g r e p o r t e d b y C r a m p to n and L l o y d ( 4 5 ) *

chrom ic o x id e

Tho r o u g h a g e p l u s

g r a i n p l u s ch ro m iu m r e p o r t e d b y C ra m p to n a n d L l o y d ( 4 5 ) w o u ld b e c o m p a r a b l e
t o t h e m e th o d o f f e e d i n g e m p lo y e d b y Kane e t a l .

( 1 0 3 ) w i t h cows w h i c h a l s o

g av e s a t i s f a c t o r y r e s u l t s ,
J a r l ( 9 9 ) f e l t t h a t t h e c h r o m i c o x i d e i n d i c a t o r m e th o d w as s u p e r i o r
t o t h e t o t a l f e c a l c o l l e c t i o n m e th o d s i n c e i t i s n o t i n f l u e n c e d a s g r e a t l y
b y v a r i a t i o n s i n t h e d a i l y am o un t o f f e c e s v o i d e d .
th e

same m e t h o d o l o g i c a l a c c u r a c y i s

(72 c o l l e c t i o n d a y s) w ith th e

a c h iev ed i n

’q u a n tita tiv e *

He s t a t e d t h a t ’’A b o u t

s ix re p e a te d ex p erim en ts

m e th o d a s i n on e e x p e r i m e n t

c o n d u c te d a c c o r d in g t o t h e i n d i c a t o r m e th o d ” .

He f e l t t h a t t h e r e w as a

c o n s t a n t r e l a t i o n b e t w e e n t h e c h r o m i c o x i d e and t h e v a r i o u s n u t r i e n t s i n
t h e r a t i o n a n d f e c e s , so t h a t a v a r i a t i o n i n f e c e s q u a n t i t y o n tw o s u c ­
c e s s i v e d a y s w o u ld n o t a f f e c t t h e c a l c u l a t e d d i g e s t i b i l i t i e s .

R ecent

d a t a o f K a n e , J a c o b s o n a n d Moore ( 1 0 4 ) show ed a v a r i a t i o n i n t h e c o n c e n ­
t r a t i o n o f ch ro m ic o x id e i n i n d i v i d u a l p a s s a g e s o f f e c e s th r o u g h o u t a 24h o u r p e r i o d w h ich d oes n o t a g re e w ith J a r l ’ s (9 9 ) a s s u m p tio n t h a t t h e r e
w as a c o n s t a n t r e l a t i o n b e t w e e n t h e

ch ro m ic o x id e and th e v a r i o u s con­

s t i t u e n t s i n th e fe c e s .
A n d e r s e n and W i n t h e r ( 3 ) f o u n d t h a t a p r e l i m i n a r y p e r i o d o f e i g h t o r
n i n e d a y s w as s u f f i c i e n t f o r r e p r e s e n t a t i v e
o x id e r a t i o m e th o d .

s a m p l e s when u s i n g t h e c h r o m i c

T h ey made a q u a n t i t a t i v e f e c e s c o l l e c t i o n f r o m f o u r

i n d i v i d u a l cow s d u r i n g

20 d a y s w h i l e t h e y r e c e i v e d a c o n s t a n t a m o u n t o f

f e e d c o n t a i n i n g 1 4 .8 2 gram s o f c h ro m ic o x i d e .

The a v e r a g e e x c r e t i o n p e r

d a y w as c a l c u l a t e d t o b e 1 4 . 6 1 g ram s o f c h r o m i c o x i d e w h ic h i s
c e n t o f th e am ount consum ed.

9 8 .6 p e r ­

S i n c e t h e y f o u n d t h e r e c o v e r y o f ch ro m iu m

8

*to b e a l w a y s l o w "they p r o p o s e d a c o r r e c t i o n b y r a i s i n g "the a m o u n t o r
c h ro m iu m f o u n d b y tw o p e r c e n t o f t h e v a l u e .

They p r e s e n t e d t a b l e s w h ic h

showed t h a t t h e c h r o m i c o x i d e i n d i c a t o r m e th o d g a v e t h e

same c o e f f i c i e n t s

of d ig e s tib ility

They a ls o con­

as t h e t o t a l f e c a l c o l l e c t i o n m e th o d .

d u c t e d t h r e e e x p e r i m e n t s w i t h n i n e cow s i n w h i c h t h e y a n a l y z e d t h e f e c e s
f r o m e a c h co w t h a t w as e x c r e t e d d u r i n g t h e d a y a n d t h e n t h e f e c e s t h a t
w ere e x c r e t e d d u r in g t h e f o ll o w i n g n i g h t .

T h ey f o u n d t h e r a t i o s o f

ch ro m ic o x id e t o th e v a r io u s n u t r i e n t s i n th e f e c e s v a r i e d b etw een d ay
a n d n i g h t f e c e s * b u t w e re n o t a l w a y s h i g h e r f o r o n e t h a n t h e o t h e r a n d
s u g g e s te d t h a t t h e p a r t i a l c o l l e c t i o n o f f e c e s sa m p le s be done th r o u g h o u t
th e e n tir e

24-hour day .

C handa* Clapham* M c h a u g h t a n d Owen ( 3 7 ) u s e d t h e c h r o m i c o x i d e r a t i o
te c h n iq u e to
d rie d g rass.

s t u d y t h e d i g e s t i b i l i t y o f c a r o t e n e b y cows a n d g o a t s f e d
W i t h g o a t s t h e t o t a l f e c a l c o l l e c t i o n t e c h n i q u e w as c o m p a r e d

w i t h t h e ch ro m iu m r a t i o

te c h n iq u e .

tio n o f th e r a tio n o f la c ta tin g

When m ix e d w i t h t h e c o n c e n t r a t e p o r ­

g o ats*

1 0 0 .0 * 9 9 . 1 , 9 9 . 1 a n d 9 6 . 0 p e r c e n t

o f t h e c h r o m i c o x i d e f e d was r e c o v e r e d i n t h e f e c e s i n f o u r e x p e r i m e n t s
w ith fo u r d if f e r e n t g o a ts.

The a p p a r e n t d i g e s t i b i l i t y o f c a r o t e n e b y t h e

g o a t w as d e t e r m i n e d b y t o t a l c o l l e c t i o n i n m e t a b o l i s m c r a t e s an d a l s o b y
t h e ch ro m iu m r a t i o

te c h n iq u e .

By t h e t o t a l c o l l e c t i o n t e c h n i q u e

g e s t i b i l i t i e s o f c a r o t e n e i n f o u r g o a ts w ere 6 8 .7 ,
p e rc e n t.

The c o r r e s p o n d i n g d i g e s t i b i l i t i e s

6 2 .7 *

th e d i­

6 1 .8 and 5 9 .6

o b t a i n e d f r o m t h e same f e c e s

s a m p l e s b y t h e c h r o m i c o x i d e r a t i o m e th o d w e re 6 7 . 4 , 6 2 .9 *

6 1 .8 and 5 8 .9

p e rc e n t.
E r i k s s o n ( 6 3 ) c o m p a re d t h e d i g e s t i o n c o e f f i c i e n t s o b t a i n e d b y t h e
t o t a l f e c a l c o l l e c t i o n m e th o d i n d i f f e r e n c e t r i a l s w i t h w e t h e r s w i t h t h o s e
c a l c u l a t e d f o r cow s b y t h e c h ro m iu m r a t i o

t e c h n i q u e and c o n c lu d e d t h a t th e

t o t a l c o l l e c t i o n m e th o d gave t h e m o s t r e l i a b l e

re su lts.

E d i n ( 6 0 ) r e p o r t e d t h a t t h e ch ro m iu m r a t i o m e th o d o f c a l c u l a t i n g t h e
d i g e s t i o n c o e f f i c i e n t s o f f e e d s w hen u s i n g a. tw o d a y c o l l e c t i o n p e r i o d
gave a s a c c u r a t e

c o e f f i c i e n t s a s t h e t o t a l c o l l e c t i o n m e th o d i n a s e v e n

to e i g h t day p e r io d .

A x e l s s o n e n d K iv im a e ( 1 7 ) c a l c u l a t e d d i g e s t i o n c o ­

e f f i c i e n t s b y t h e c h ro m iu m r a t i o
t i o n - e x c r o t i o n r a t i o s on th e

p r o c e d u r e and from t h e n u t r i e n t

same s a m p l e s c o l l e c t e d a t two d a y i n t e r v a l s

f r o m t h r e e w e t h e r s o v e r a p e r i o d o f 44 d a y s .
e f f i c i e n t s o f th e
c a lc u la tio n .

22 p e r i o d s w e r e n e a r l y t h e

The a v e r a g e d i g e s t i o n c o ­
same f o r t h e two m e t h o d s o f

The d i g e s t i o n c o e f f i c i e n t s c a l c u l a t e d b y t h e t o t a l c o l l e c t i o n

a n d t h e c h ro m iu m r a t i o
and 7 1 .2 ; p r o te i n *
fre e e x tra c t*

c o n su m p -

te c h n iq u e s r e s p e c t i v e l y w ere; o rg a n ic m a tte r 7 1 .7

7 4 . 5 a n d 7 4 . 2 ; 'O ther e x t r a c t *

7 7 .2 and 7 6 .8 ; and c ru d e f i b e r *

7 0 .1 and 3 9 .3 ; n i t r o g e n -

5 3 .7 an d 5 2 .9 .

T hey f u r t h e r

sho w ed t h a t t h e a v e r a g e d i g e s t i o n c o e f f i c i e n t w as i n d e p e n d e n t o f t h e
le n g th o f th e c o l l e c t i o n p e rio d

(tw o t o t e n d a y s ) b u t t h a t t h e

sta n d a rd

d e v i a tio n d e c re a s e d r a p id l y w ith in c re a s e d le n g th o f th e p e r io d .
L i g n in R a tio T ec h n iq u e
L ig n in h a s b e e n q u it e w id e ly s tu d ie d d u r in g th e p a s t few y e a r s
if it

c o u l d be e s t a b l i s h e d t h a t i t

i s an i n d i g e s t i b l e

su b stan ce*

sin c e *

i t w o u ld

a ls o m eet th e re q u ire m e n ts o f b ein g a n a t u r a l c o n s t i t u e n t o f th e p l a n t
m a te ria l.
L i g n i n h a s b e e n r e p o r t e d t o be i n d i g e s t i b l e b y s t e e r s ( 4 6 ) ; b y cows
o n a m i x e d f e e d an d b y s h e e p o n d r i e d S u d a n g r a s s ( 6 2 ) ; b y cows o n a l ­
f a l f a h a y ( 8 4 ) ; b y sh eep ( 8 3 ) ; by sheep

011

m ix e d f e e d s

(1 7 8 ); by sheep

on K orean le s p e d e z a hay c u t a t fo u r s ta g e s o f m a tu r it y (4 1 ); by s t e e r s
on p a s t u r e fo ra g e

( 6 9 ) ; b y cow s o n a r a t i o n o f a l f a l f a

sila g e ,

corn s ila g e

a n d g r a i n , a n d a l s o o n a r a t i o n o f a l f a l f a hay * c o r n s i l a g e a n d g r a i n
(1 0 3 );

a n d b y cow s f e d w h e a t s t r a w ( 6 6 ) .

10

S w i f t e^t &1. ( 1 7 8 ) h a d 16 t r i a l s u s i n g s h e e p o n m ix e d r a t i o n s
c o m p a r e d th© d i g e s t i b i l i t y

c o e ffic ie n ts

and

c a lc u la te d by th e lig n in r a t i o

m e th o d w i t h t h e c o n v e n t i o n a l t o t a l c o l l e c t i o n m e t h o d and. f o u n d t h e two t o
c h e c k v e r y c l o s e l y and s t a n d a r d e r r o r s o f th e d i g e s t i o n c o e f f i c i e n t s d e ­
t e r m i n e d b y t h e tw o m e th o d s w e r e o f t h e sam e g e n e r a l . m a g n i t u d e .
F o r b e s a n d G - a r r ig u s ( 7 0 ) u s e d t h e l i g n i n r a t i o
d ig e stib ility

te c h n iq u e to

o f p a s t u r e f o r a g e s by s t e e r s a n d w e t h e r s .

covery o f lig n in in

stu d y th e

The a v e r a g e r e ­

s e v e n d i g e s t i o n t r i a l s w i t h s t e e r s was 1 0 2 + 7 p e r c e n t .

C o m p a riso n s o f t h e d r y m a t t e r i n t a k e s and t h e d i g e s t i b i l i t y

c o e ffic ie n ts

o f t h e d r y m a t t e r a s c a l c u l a t e d b y t h e l i g n i n r a t i o m e th o d a n d t h e p l a n t
p ig m e n t r a t i o

sho w ed e x t r e m e v a r i a t i o n s

H a rris

F o r a g e c o n s u m p t i o n a s d e t e r m i n e d by t h e l i g n i n r a t i o

(40).

i n th e

s t u d y r e p o r t e d b y Cook and
te c h ­

n iq u e ^ how ever, a g re e d c l o s e l y w ith th e c a l c u l a t e d d ry m a tte r i n t a k e s
com m only a c c e p t e d f o r t h e v a r i o u s s i z e s o f s h e e p .

In a d d itio n , th e c a l ­

c u l a t e d d i g e s t i b i l i t y o f t h e d r y m a t t e r by th e u s e o f t h e l i g n i n r a t i o
t e c h n i q u e co m p a re d f a v o r a b l y w i t h t h e r e s u l t s o b t a i n e d by* o t h e r i n v e s t i ­
g a t o r s on s i m i l a r f o r a g e s .

T h i s was n o t t r u e w i t h a l l

f o r c a l c u l a t i o n s raa.de b y t h e p l a n t p i g m e n t r a t i o

sp e c ie s

te c h n iq u e .

f i l l i s , M a t r o n s arid M a y n a rd ( 6 2 ) d e t e r m i n e d d i g e s t i b i l i t y
by th e
ra tio

c o n v e n tio n a l t o t a l

c o e ffic ie n ts

f e c a l c o l l e c t i o n te c } m iq u o and a l s o by t h e l i g n i n

te c h n iq u e u s in g v a rio u s

secu red v ery c lo se

stu d ie d

r a t i o n s w i t h c o w s , r a b b i t s and sheet)*

They

c h e c k s b e t w e e n t h e tw o m e th o d s f o r d i g e s t i b i l i t y o f t h e

d r y m a t t e r and t h e o t h e r f e e d c o n s t i t u e n t s .
sm all d a i ly v a r i a t i o n s

in th o

T h ey f u r t h e r

lig n in c o n te n t of feces

f e d t i m o t h y h a y , w h i c h w o u ld make t h e

show ed v e r y

from t h r e e

six c e p

sh o rte n e d c o l l e c t i o n p e r io d o f th e

p a r t i a l f e c a l c o l l e c t i o n t e c l n i i q u e sat?, s f a c t o r y .
H a l o , D u n c a n a n d H u ffm a n ( 8 4 ) p r o p o s e d t h a t l i g n i n be u s e d a s a n
in d ic a to r fo r th e

s t u d v o f d i g e s t i b i l i t y i n t h o ru m e n s i n c e l i g n i n d i d

11

n o t: a p p e a r t o be a p p r e c i a b l y d i g e s t e d i n t h e rum en e v e n t h r o u g h t o t a l
d i g e s t i o n ran g ed up to
fro m n e g a tiv e v a lu e s to

2 3 .7 p e r c e n t*

D i g e s t i b i l i t y o f l i g n i n ra n g in g

29 p e r c e n t 'were r e p o r t e d b y F o r b e s and S w i f t

(7 2 ).
F o r b e s a n d G a r r i g u s (70^) r e p o r t e d a t o t a l o f 70 g r a z i n g t r i a l s w i t h
s t e e r s and w e th e r s u s in g th e
tria ls
to

lig n in ra tio

te c h n iq u e

an d c o n d u c t e d p e r i o d i c

i n d i g e s t i o n s t a l l s u s i n g c u t f o r a g e and t o t a l f e c a l c o l l e c t i o n s

c o n firm th e r e l i a b i l i t y

o f th e lig n in r a ti o

te c h n iq u e .

The a v e r a g e

r e c o v e r y o f l i g n i n f r o m s t e e r s f e d i n t h e d i g e s t i o n s t a l l s w a s 106 + 5 . 8
p e r c e n t , a n d f r o m la m b s t h e

a v e r a g e r e c o v e r y w as 111 + 8 , 7 p e r c e n t .

They

d i d n o t p r e s e n t d a t a , b u t s t a t e d t h a t t h e y i n v e s t i g a t e d th e m e th o x y l c o n ­
t e n t o f th e f o r a g e l i g n i n and th e f c c e s l i g n i n b u t co u ld n o t a c c o u n t f o r
th e

s l i g h t l y h ig h re c o v e rie s .

c o e f f i c i e n t s o b t a i n e d by t h e

A c tu a l co m p ariso n s o f th e d i g e s t i b i l i t y
c o n v e n t i o n a l m e th o d and t h e l i g n i n r a t i o

m e th o d a r e made i n a l a t e r p a p e r b y F o r b e s and G a r r i g u s
good a g r e e m e n t b e t w e e n t h e tw o m e t h o d s a r e e v i d e n t .

(71) and v e ry

D ig e stio n c o e f f ic ie n ts

o b t a i n e d f o r l i g p i n b y t h e t o t a l c o l l e c t i o n t e c h n i q u e w e r e lo w e x c e p t f o r
h ig h n e g a tiv e

c o e ffic ie n ts

i n f o u r t r i a l s w i t h w e t h e r s b e d d e d w i t h wood

s h a v in g s.
M a r s h a l l ( 1 1 6 ) u s e d t h e l i g n i n r a t i o m e th o d t o

stu d y th e d i g e s t i b i l i t y

o f p e n t o s a n s o f h a y i n v a r i o u s a r e a s o f t h e d i g e s t i v e t r a c t o f two s h e e p .
V a rio u s d e g re e s o f d i g e s t i o n o f l i g n i n have been re p o rte d

by v a r i o u s

w o r k e r s , b u t c o m p a riso n s b etw ee n d i f f e r e n t e x p e rim e n ts a rc d i f f i c u l t to
e v a lu a te

s i n c e d i f f e r e n t a n a l y t i c a l m e t h o d s and d i f f e r e n t a n i m a l

sp e c ie s

w ere u s e d .
C r a m p to n a n d M ay n ard ( 4 6 ) r e p o r t e d l i g n i n t o

be a s h i g h a s 30 p e r c e n t

o r m o re d i g e s t i b l e i n f e e d b a r l e y , w h e a t s c r e e n i n g s a n d f e e d o a t s w hen

d e t e r m i n e d b y t h e i r m e t h o d , b u t w as a l m o s t c o m p l e t e l y i n d i g e s t i b l e w hen
d e te rm in e d

’’b y d i f f e r e n c e a s p r o p o s e d b y C r a m p to n a n d W h i t i n g ( 4 7 ) .

E v i d e n c e t h a t some c h a n g e may o c c u r i n l i g n i n a s i t p a s s e d t h r o u g h
th e d i g e s t i v e t r a c t o f ru m in a n ts h a s b een p r e s e n te d by s e v e r a l i n v e s t i g a ­
to rs.

C sonka, P h i l l i p s

and J o n e s (4 8 ) re p o r te d , a d e c re a .se i n m e th o x y l

gro u p s o f l i g n i n t h a t had b een th ro u g h th e ru m in an t d i g e s t i v e t r a c t .
I

P a ^ u r a n d DeLong ( 1 4 5 ) f o u n d a n i n c r e a s e d e x c r e t i o n o f b e n z o i c a n d
h i p p u r i c a c i d s i n t h e u r i n e o f s h e e p f e d i n c r e a s e d a m o u n ts o f l i g n i n .
The i n c r e a s e d u r i n a r y c o n c e n t r a t i o n o f a r o m a t i c a c i d s w e r e b e l i e v e d t o b e
e x c r e t o r y p r o d u c ts o f th e a ro m a tic r i n g s from th e d e g r a d a tio n o f l i g n i n .
L ig n in is o la te d

f r o m f o r a g e s y i e l d e d up t o

a l d e h y d e s w hen t r e a t e d w i t h n i t r o b e n z e n e

20 p e r c e n t o f i t s w e i g h t a s

in a l k a l i , b ut lig n in is o la te d

f r o m f e c e s y i e l d e d no a l d e h y d e s w hen c o r n u a r a b l y t i ' e a t e d i n e x p e r i m e n t s o f
B o n d i a n d M eyer ( 2 8 ) .
te n t,

T h ey a l s o f o u n d a s l i g h t i n c r e a s e i n n i t r o g e n c o n ­

b u t no c h a n g e i n t h e m e t h o x y l c o n t e n t o f l i g n i n i s o l a t e d

a s com pared t o t h a t i s o l a t e d

from f o r a g e s .

fro m f e c c s

F o r b e s an d G a r r i g u s

(7 1 ) found

no c h a n g e i n t h e m e t h o x y l c o n t e n t o f f o r a g e l i g n i n i n t h e d i g e s t i v e t r a c t
o f sheep.
p a lo h e im o

( 1 4 s , 144) and P h i l l i p s

(1 4 6 ) have d e te rm in e d th e n it r o g e n

c o n t e n t o f c r u d e l i g n i n an d d e d u c t e d f r o m t h e c r u d e l i g n i n p e r c e n t a g e o n
th e a ssu m p tio n t h a t th e n itr o g e n o u s r e s id u e i s a p r o t e i n .
d i f f i c u l t y in o b ta in in g r e lia b le
te ria ls

The p r i n c i p a l

f i g u r e s f o r l i g n i n i n p r o t e i n - r i c h ma­

i s t h e r e m o v a l o f t h e p r o t e i n w i t h o u t r e m o v i n g a. p a r t o f t h e l i g n i n .

H o m a n and J e n k i n s

( 1 3 9 ) f e l t t h a t a g r e a t e r e r r o r m i g h t be made i n c a l ­

c u l a t i n g t h i s n i t r o g e n a s p r o t e i n t h a n by n o t c o r r e c t i n g a t a l l .
t h a t no one h a d e v e r s u c c e e d e d i n i s o l a t i n g
p a r a t i o n from s u c c u le n t p l a n t t i s s u e

a n itro g e n -fre e

The f a c t

lig n in p re­

l e d M a c D o u g a ll a n d DeLong ( 1 1 4 ) t o

13

g iv e

s tro n g c o n s id e ra tio n to

th e p o s s i b i l i t y t h a t n itr o g e n i s a fu n d a ­

m e n ta l com ponent o f th e l i g n i n o f s u c c u le n t p l a n t m a t e r i a l s .

Bondi and

M ey er ( 2 8 ) p r e p a r e d l i g n i n s f r o m a n u m b e r o f a n n u a l g r a s s e s and le g u m e s
by e x t r a c t i o n w ith d i l u t e a l k a l i .

The p r e p a r a t i o n s

c o n ta in e d n itr o g e n

w h i c h t h e y f e l t w as n o t d u e t o c o n t a m i n a t i o n w i t h p r o t e i n s , b u t s e e m e d t o
be a c h a r a c t e r i s t i c

com ponent o f t h e l i g n i n m o le c u le i t s e l f .

They b e l i e v e d

t h a t th e c o n sta n c y o f th e n it r o g e n c o n te n t o f t h e i r l i g n i n p r e p a r a t io n s
from th e

same p l a n t m a t e r i a l i n c o n s e c u t i v e e x t r a c t i o n s s u p p o r t e d t h e i r

o p in io n .

They a l s o

re m o v e d m o s t o f t h e p r o t e i n f r o m t h e p l a n t m a t e r i a l

by tr e a tm e n t w ith v e ry d i l u t e
in d ilu te

s o d iu m h y d r o x i d e o r b y t h e a c t i o n o f p e p s i n

h y d r o c h l o r i c a c i d b e f o r e e x t r a c t i n g t h e l i g n i n and fo u n d t h a t

t h e l i g n i n from p l a n t s g iv e n t h e s e p r o l i m i n a r y t r e a t m e n t s

showed a p p r o x i ­

m a te ly th e

same n i t r o g e n c o n t e n t a s t h a t f r o m p l a n t m a t e r i a l w h i c h d i d n o t

re c e iv e i t .

De Man and De H eus ( 5 2 ) h y d r o l y z e d l i g n i n p r e p a r a t i o n s f r o m

a s a m p le o f L o l iu m p e r e n n e w i t h
th e ty r o s in e

and try p to p h a n e

stro n g

s o d iu m h y d r o x i d e a n d d e t e r m i n e d

c o n t e n t s and a l s o c a l c u l a t e d t h e t y r o s i n e -

n i t r o g e n and t r y p t o p h a n e - n i t r o g e n a s p e r c e n t a g e o f t h e t o t a l n i t r o g e n i n
t h e s e p r e p a r a t i o n s a n d c o m p a re d t h e s e f i g u r e s w i t h t h e
tru e p r o te in o f th e g ra s s .

Tho t y r o s i n e - n i t r o g e n c a l c u l a t e d a s p e r c e n t a g e

o f t h e t o t a l n i t r o g e n o f th o p r e p a r a t i o n s

co rresp o n d ed c lo s e ly w ith th e

f i g u r e f o r t h e t r u e p r o t e i n o f L o l iu m p e r e n n e .
f o r try p to p h a n e

c o m p o sitio n o f th e

The c o r r e s p o n d i n g f i g u r e s

checked o n ly in th e ca se o f l i g n i n p re p a re d a c c o rd in g to

t h e m e th o d o f B ondi and M eyer ( 2 8 ) w h i c h u s e s no s t r o n g a c i d t o d e s t r o y
try p to p h a n e .

These r e s u l t s

le n d

su p p o rt to th e

e q u i v a l e n t fro m th e n i t r o g e n r e s i d u e s i n th e

c a lc u la tio n of p ro te in

lig n in .

Thomas and A r m s t r o n g

( 1 7 9 ) c o m p a r e d t h e Horman and J e n k i n s ( 1 3 9 ) , the- C ra m p to n a n d M ay nard ( 4 6 ) ,
a n d t h e E l l i s , M atron© a r d M ay n ard ( 6 2 ) m e th o d s o f d e t e r m i n i n g l i g n i n a l l

o f w h i c h i n v o l v e t h e u s e o f ,72 p e r c e n t s u l f u r i c

a c id .

The l i g n i n y i e l d s

o b t a i n e d w i t h t h e m e th o d o f E l l i s , M a t r o n e a n d M a y n a rd w e re a p p r e c i a b l y
h i g h e r t h a n t h o s e o f t h e m e th o d o f Horman a n d J e n k i n s .

bhen a p r o t e i n

c o r r e c t i o n f a c t o r w as u s e d t h e r e s u l t s o f t h e tw o m e th o d s w e r e co m p e.rs.b le.
Thomas a n d A r m s t r o n g ( 1 7 9 ) f u r t h e r show ed t h a t a c i d h y d r o l y s a t e s f r o m
c r u d e l i g n i n i s o l a t e d f r o m p l a n t m a t e r i a l a n d f r o m f e c e s c o n t a i n e d a m in o a c id s.
I n d i g e s t i b l e P r o t e i n R a t io T ec h n iq u e
S e v e r a l a p p r o a c h e s h a v e b e e n made t o t h e u s e o f f o r a g e o r f e c e s p r o ­
te in ,

o r a c o m b in a tio n o f t h e s e ,

ity .

The p r i n c i p a l a d v a n t a g e o f t h i s

stu d ie s is th a t i t

fo r th e

c a lc u la tio n o f fo rag e d i g e s t i b i l ­

te c h n iq u e f o r p a s tu r e d i g e s t i b i l i t y

e lim in a te s a la rg e p a r t of th e p a s tu re

sam p lin g e r r o r .

S in c e g ra z e d f o r a g e i s e x tre m e ly d i f f i c u l t t o

s a m p le t h a t w h i c h i s

s e n ta tiv e o f th e

some e r r o r i s p e r m i s s a b l e

fo ra g e g ra z e d by th e a n im a l,

rep re­

i n th e c a lc u la tio n o f feed in ta k e or d i g e s t i b i l i t y o f p a s tu re by th e n i t r o ­
gen c o n te n t and s t i l l
a tte m p ts to

s e c u r e g r e a t e r a c c u r a c y t h a n may be a t t a i n e d b y

s a m p le t h e g r a z e d f o r a g e .

G a llu p and B r ig g s (7 8 ) b e l i e v e d t h a t a c o n s t a n t r e l a t i o n s h i p e x i s t e d
b e t w e e n t h e a m o u n t o f f e c a l n i t r o g e n an d t h e d r y m a t t e r i n t a k e ,
o f t h e am ount o f p r o t e i n i n t h e f o r a g e .
M itc h e ll (2 6 ) have p r e s e n te d
n o t h o ld .

F orbes

d ata to

reg ard less

B o th F o r b e s \, 6 7 ) an d B l a x t e r a n d

show t h a t a c o n s t a n t r e l a t i o n s h i p d o e s

(6 7 ) found t h a t th e d a t a f o r f r e s h

grass in d ic a te d th a t

t h e t o t a l f e c a l n i t r o g e n v a r i e d to o w id e l y to be u s e d a s s u g g e s te d by
G a llu p and B rig g s

(7 8 ).

7/ a s

i n f e c a l n i t r o g e n e x c r e t i o n p e r 1 0 0 grams o f d r y m a t t e r

a ste a d y r i s e

in ta k e

He a l s o f o u n d t h a t w i t h d r i e d r o u g h a g e s t h e r e

as th e p e r c e n ta g e o f p r o t e i n i n th e

( 1 1 1 ) p r o p o s e d a m e th o d f o r t h e

roughage i n c r e a s e d .

c a lc u la tio n of o rg a n ic l e t t e r

L a n c a ste r
d ig e stib ility

17

H e lle r , Breed le v 1© and L ik ely (9 0 ) used the normal ir o n c o n ten t o f a
r a tio n a s th e in d ic a to r substance fo r determ ining th e d i g e s t i b i l i t y o f
r a tio n s f o r rate*
S i l i c a R atio Technique
The s i l i c a r a tio tech n iq u e fo r th e determ ination o f d i g e s t i b i l i t y
o f fe e d s has u t i l i z e d both the n a tu ra lly -co n ta in ed s i l i c a and a lso
added amounts o f s ilic a *
Gallup (7 7 ) used th e s i l i c a r a tio technique w ith r a ts on a d i e t con­
ta in in g one percent o f added s i l i c a and secured r e s u lt s which checked
c lo s e l y w ith th ose ob tain ed by standard methods*

Gallup and Kuhlman (8 0 )

used cows on a r a tio n which con tain ed approxim ately th ree p ercen t o f
n a tu r a lly -o c c u r r in g s i l i c a and 0*5 p ercen t o f added iro n oxid e and secured
r e s u lt s which in d ic a te d th a t th e s i l i c a n a tu r a lly contained in th e feed
was su p erior to ir o n oxid e as an in d ic a to r substance in d ig e s tio n t r i a l s *
A la t e r t r i a l w ith mung bean s ila g e was conducted by Gallup and Kuhlman
(8 1 ).

T his mung bean s ila g e contained approxim ately 20 p ercen t o f s i l i c a

which was more than s i x tim es th e co n cen tra tio n p r e v io u sly u sed .

They

found th e s i l i c a r a tio techn iqu e u n s a tis fa c to r y because th e r a tio o f food
c o n s titu e n t to s i l i c a r a tio o f th e fe e d v a r ie d from day to day.

The r a tio

o f f e c e s c o n s titu e n ts to s i l i c a content showed such wide v a r ia tio n s during
a 24-hour period th a t random sampling o f th e f e c e s was n o t j u s t i f i a b l e .
While th ey did n o t determ ine th e cause o f th e se v a r ia t io n s , th ey p o stu la te d
th a t th e y could be due to an uneven d is tr ib u tio n o f th e s i l i c a in the feed
and a ls o t o s t r a t i f i c a t i o n and l o s s o f s i l i c a in i t s passage through the
in te s tin a l tr a c t.

G allup, Hobbs and Briggs (79) made a study o f a s e r ie s

o f r a tio n s u sin g s te e r s and sheep fo r comparison o f the s i l i c a r a tio te c h ­
nique w ith th e standard method and fo r c a lc u la tio n o f s i l i c a recovery .

The

recovery o f in g e ste d s i l i c a was p r a c t ic a lly q u a n tita tiv e when th e s te e r s
were in stan ch ion s and th e f e c e s c o lle c te d semimanually.

'When th e s te e r s

18

w e r e I n d r y l o t a n d th@ f e c e s c o l l e c t e d i n c a n v a s s a c k s , t h e
c r e t i o n o f f e c a l s i l i c a exceeded th e c a lc u la te d
Yfhen t h e

average ex­

in ta k e by ab o u t lu p e r c e n t,

s t e e r s w e r e o n p a s t u r e , f e c a l s i l i c a e x c r e t i o n w as 66 p e r c e n t

h ig h e r th a n th e c a l c u la te d i n t a k e , p ro b a b ly due to th e in g e s tio n o f d i r t
by t h e g r a z i n g a n i m a l s .
s ilic a

In th e

sheep t r i a l s

I n m e ta b o lism c r a t e s ,

c o n t e n t a v e ra g e d 107 p e r c e n t o f t h e c a l c u l a t e d i n t a k e .

fecal

They f e l t

t h a t c o n t a m i n a t i o n o c c u r r e d w hen t h e f e c e s w e r e e x p o s e d t o b a r n d u s t d u r i n g
th e day o f c o l l e c t i o n s .
n iq u e i s

T h eir r e s u l t s

in d ic a te t h a t th e

s ilic a ra tio

te c h ­

a d a p ta b le to d i g e s t i o n t r i a l s w ith s t e e r s and sheep i f th e r e ­

covery o f s i l i c a i s

re a so n a b ly c lo se to

a re a p p a r e n tly n e c e s s a r y i n u sin g th e
ta m in a tio n o f th e

s a m p le a t a m inim um .

100 p e r c e n t .

s ilic a ra tio

E x tra p re c a u tio n s

te c h n iq u e to keep con­

D ru c e and iY il lc o x ( 5 6 ) s e c u r e d

good r e c o v e r y o f n a t u r a l f e e d s i l i c a f r o m t h e f e c a l m a t e r i a l o f r a b b i t s
and t h u s t h e

s ilic a

r a t i o t e c h n i q u e gave r e s u l t s

v e n t i o n a l t o t a l e o 3 .1 © c tio n m e th o d *
to

th e

s i l i c a r a t i o m e th o d ,

c o m p arab le w i t h t h e

They w e r e a w a re o f c e r t a i n o b j e c t i o n s

such as th e v a r i a t i o n i n th e re c o v e ry v a lu e s

b e t w e e n i n d i v i d u a l a n i m a l s and t h e p o s s i b i l i t y ? - o f s i l i c a
from th e

s o il in p a stu re

con­

c o n ta m in a tio n

stu d ie s.

P l a n t P ig m e n t R a t io T ec h n iq u e
The u s e o f a n a t u r a l l y - o c c u r r i n g p l a n t p i g m e n t o r g r o u p o f p i g m e n t s
w h ic h a r e f u l l y

re c o v e ra b le i n th e f e c e s h as th e

n a tu ra lly - o c c u r r in g feed c o n s titu e n ts
th e d i g e s t i b i l i t y o f th e fe e d

in th a t,

same a d v a n t a g e a s o t h e r

in a d d itio n to

d e te rm in in g

s tu d ie d , th e y w i l l a ls o p e rm it an I n d i r e c t

m easurem ent o f th e q u a n t i t y o f p a s tu r e

h e r b a g e c o n su m ed b y e r a s i n g a n i m a l s .

The f i r s t r e p o r t o f a n i n d i g e s t i b l e p l a n t p i g m e n t o r g r o u p o f p i g m e n t s
w a s made b y R e i d e t a l .

( 1 5 5 , 1 5 6 ) u s i n g 85 p e r c e n t a c e t o n e a s t h e

f o r e x t r a c t i n g t h e p i g m e n t o r p i g m e n t s f r o m t h e f e e d and, f e c c s .
m e th o d w i l l be r e f e r r e d

to

as th e p l a n t p ig m e n t r a t i o

te c h n iq u o .

so lv e n t

T h is
E stim a ­

19

t i o n s o f t h e c o n c e n t r a t i o n o f p l a n t p i g m e n t p r e s e n t i n t h e 85 p e r c e n t
a c e t o n e e x t r a c t s o f t h e f e e d a n d f e c e s -were mad© f r o m t h e am o u n t o f l i g h t
ab so rb ed by th e

d i l u t e d e x t r a c t s a t 40 6 m i l l i m i c r o n s wave l e n g t h u s i n g a

Be ckm ann s p e c t r o pho t o m e t e r .
The r e c o v e r y o f t h e e x t r a c t e d p l a n t p i g m e n t s i n t h e f e c e s w e r e v e r y
c l o s e t o 100 p e r c e n t i n a l l o f t h e m a t e r i a l s s t u d i e d an d t h e c a l c u l a t e d
d i g e s t i o n c o e f f i c i e n t s fro m t h e p l a n t p ig m e n t r a t i o s

show ed e x c e l l e n t

agreem ent w ith th e c o n v e n tio n a l t o t a l f e c a l c o l l e c t i o n te c h n iq u e .

Com­

p a r i s o n s w e r e m ade b e t w e e n f i e l d - c u r e d h a y , b a r n - c u r e d h a y , o v e n - d r i e d
h ay , hay -cro p s ila g e ,

la d in o c lo v e r h a y , and t h r e e

sta g e s o f p a s tu re

g rass.
W h ile R e id e t a l ,

(1 5 6 ) d id n o t r e p o r t on t h e i d e n t i t y o f t h e p ig m e n t

o r p i g m e n t s t h a t w e re r e s p o n s i b l e f o r t h e l i g h t a b s o r p t i o n a t 406 m i l l i ­
m i c r o n s , t h e y f e l t t h a t o n e s u b s t a n c e w as l a r g e l y r e s p o n s i b l e f o r t h e
a b so rp tio n o bserved.
M c C u ll o u g h , E l l i o t a n d B a s t i n ( 1 2 2 ) h a v e m ade a p p l i c a t i o n o f t h e
p l a n t p ig m en t r a t i o
th e

t e c h n i q u e d e s c r i b e d b y R e i d crfc a l .

(156) f o r s tu d y in g

s e a s o n a l ch an g es i n t h e d i g e s t i b i l i t y o f th e d ry m a tte r and p r o t e i n

o f p a s t u r e h e r b a g e t r e a t e d w i t h v a r i o u s ©mount o f b a r n y a r d m a n u r e , b u t
d i d n o t make a c o m p a r i s o n w i t h a n y o t h e r m eth o d o f d e t e r m i n i n g d i g e s t i b i l ­
ity

c o e ffic ie n ts.
The c o m m i t t e e o f jj jii e r ic a n S o c i e t i e s o f A gronom y, D a i r y S c i e n c e ,

A n im a l p r o d u c t i o n an d R ange M an ag em ent ( 3 9 ) r e p o r t e d o n p a s t u r e
r e s e a r c h t e c h n i q u e and p r o p o s e d t h a t t h e p l a n t p i g m e n t r a t i o
re p la c e th e li g n i n r a t i o te c h n iq u e .
c o m p a riso n o f th e

Cook and H a r r i s

and ra n g e

m e th o d s h o u l d

( 4 0 ) made a d i r e c t

l i g n i n r a t i o m e th o d and t h e p l a n t p i g m e n t r a t i o m e th o d

u s i n g s e v e n w e th e r sheep g ra z e d on f i v e

fo rag e

sp e c ie s in n o rth w e ste rn

20

U ta h t h a t w ere t y p i c a l o f t h e n o r t h e r n d e s e r t s h ru b v e g e t a t i o n .

A ll

s p e c i e s "were i n a d o r m a n t s t a g e a n d d i d n o t r e p r e s e n t t y p i c a l l u s h g ro w in g v e g e ta tio n .

F e c e s w ere c o l l e c t e d fro m f e c a l b a g s t h a t w ere e m p tie d

tw ic e d a i l y and t h e sam p les c o m p o site d o v e r a s i x - d a y g r a z i n g p e r io d f o l l o w ­
in g an e ig h t- d a y p r e li m i n a r y p e r io d .

F o r a g e s a m p l e s w e re t a k e n b y m a n u a l l y

p l u c k i n g t h e p o r t i o n s o f t h e p l a n t t h a t w e r e o b s e r v e d t o be g r a z e d by t h e
a n im a ls.

The ©mount o f p l a n t p i g j n e n t r e c o v e r e d i n t h e f e c e s o f s h e e p

g r a z i n g b i g s a g e b r u s h a n d b l a c k s a g e w as c o n s i d e r a b l y l e s s t h a n t h a t c o n ­
sum ed.
tie s

T h i s g a v e n e g a t i v e d i g e s t i o n c o e f f i c i e n t s a n d e x t r e m e l y lo w q u a n t i ­

o f e stim a te d d ry m a tte r in ta k e .

f e c e s o f sheep g ra z in g s q u i r r e l t a i l

The p l a n t p i g m e n t r e c o v e r y i n t h e
g r a s s seem ed v e r y h i g h a n d g ave a

c a lc u la te d c o e ffic ie n t of d ig e s tib ility

f o r d ry m a t t e r o f 6 8 .7 p e r c e n t

w h i c h w as m a r k e d l y h i g h e r t h a n a n y o t h e r o f t h e m a t u r e d o r m a n t d e s e r t
sp e c ie s

s t u d i e d a n d seem s e r r o n e o u s l y h i g h s i n c e i t

50 p e r c e n t h i g h e r t h a n t h e d i g e s t i b i l i t y
n in ra tio
ra tio

te c h n iq u e .

T h is i s

is

a p p ro x im a te ly

c o e f f ic ie n t o b ta in e d by th e l i g -

th e f i r s t i n d i c a t i o n t h a t t h e p l a n t p ig m e n t

t e c h n i q u e w i l l n o t w o rk w i t h c e r t a i n

s p e c ie s o f forage*

n i f i c a n t t h a t t h e y se c u re d c l o s e ch o ck s b etw een th e l i g n i n
and t h e p l a n t p ig m e n t r a t i o
F e id e t a l .

r a t i o m e th o d

m e th o d w hen u s i n g a l f a l f a h e y .

g r a s s c o n su m e d en d t h e f e c e s v o i d e d a r e r e l a t e d t o

th e degree o f d i g e s t i b i l i t y ,

feces

s ig ­

( 1 5 4 , 1 5 5 , 1 5 6 ) h a v e r e c e n t l y shown t h a t t h e p l a n t p i g ­

ment c o n te n t o f th e

ste m r a t i o .

I t is

The r e l a t i o n s h i p

t o t h e s t a g e o f g r o w t h , and t o t h e l e a f t o
b etw ee n th e p l a n t p ig m e n t c o n t e n t o f d ry

and t h a t o f t h e co n su m ed f o r a g e o n a d r y w e i g h t b a s i s w as e s t a b ­

li s h e d w ith c o n v e n tio n a l d ig e s tio n t r i a l s
Y = ( 0 . 0 9 25 X + 1 5 7 . 3 3 8 3 l o g X) -

and i s e x p r e s s e d

2 4 2 .1 1 8 1 , w here

by th e

e q u a tio n :

Y = p l a n t p i g m e n t c o n t e n t p e r u n i t o f d r y m a t t e r o f co n su m ed f o r a g e a n d
X = p l a n t p ig m e n t c o n t e n t p e r u n i t o f f e c a l d r y m a t t e r .
C o n s id e r in g th e d i f f i c u l t i e s e n c o u n te r e d i n m a n u a lly sa m p lin g p a s t u r e
f o r a g e t h a t i s c o m p a ra b le t o t h a t a c t u a l l y g ra z e d b y t h e

a n im a l, t h i s

m e th o d s h o u l d o f f e r a n e x c e l l e n t m e an s o f o b t a i n i n g a r e p r e s e n t a t i v e

con­

c e n t r a t i o n o f p l a n t p i g m e n t i n t h e f o r a g e c o n su m ed s i m p l y b y a n a l y z i n g
t h e f e c e s and a p p l y i n g t h e e q u a t i o n .

R eid o t a l .

(1 5 7 , 158) have a l s o

fo u n d t h a t a d i f f e r e n t r e l a t i o n s h i p h o ld s b etw ee n th e p l a n t p ig m e n t con­
c e n t r a t i o n i n d r y h a y s an d t h e i r

c o rre sp o n d in g fe c e s th a n t h a t re p o r te d

w ith f r e s h green g ra s s e s .
The p l a n t p i g m e n t r a t i o

t e c h n i q u e h a s b e e n u s e d b y h o l l e r , H i l l and

L u n d q u i s t (1 3 0 ) t o d e t e r m in e t h e a p p a r e n t d i g e s t i b i l i t y o f f o r a g e

grazed

b y m i l k i n g c o w s , b u t t h e m e th o d w as n o t c o m p a r e d w i t h a n y o t h e r t e c h n i q u e .
O th e r D i g e s t i o n T r i a l T e c h n iq u e s
In c re a se d i n t e r e s t in th e a p p lic a tio n o f th e r a t i o
i z in g e i t h e r n a tu r a lly - o c c u r rin g p la n t su b stan ces or
in d i c a to r s f o r th e d e te rm in a tio n of d i g e s t i b i l i t y

te c h n iq u e s u t i l ­

ad d ed m a t e r i a l s a s

in ru m in an ts w i l l un­

d o u b t e d l y r e v e a l a nu m b e r o f u s e f u l s u b s t a n c e s i n b o t h o f t h e s e c l a s s e s .
C o r b i n a n d F o r b e s (4-2) f e d e l e v e n la m b s g ro u n d a l f a l f a t w i c e d a i l y
and g av e n i n e t e s t la m b s e a c h 0 . 5

g ram o f a n t h r a q u i n o n e v i o l e t b e f o r e e a c h

f e e d i n g a n d t h e two c o n t r o l la m b s r e c e i v e d p l a c e b o s .
fro m th e f e c e s w i t h benzene i n a

11/ a r i n g

The dye ’was e x t r a c t e d

m i c r o - b l e n d e r and d e n s i t y d e t e r ­

m i n a t i o n s w e r e made w i t h a Beckman s p e c t r o p h o t o m e t e r o n t h e b e n z e n e
s o l u t i o n o f t h e d y e a t 578 m i l l i m i c r o n s .

R e c o v e r ie s o f a n th ra q u in o n e-

v i o l c t f r o m t h e f e c e s o f n i n e la m b s r a n g e d f r o m 9 6 , 4 t o 1 0 6 . 0 p e r c e n t
w ith an a v e ra g e o f 1 0 0 .5 p e r c e n t .

T h is a s s u re d t h a t d i g e s t i b i l i t y co ­

e f f i c i e n t 's c a l c u l a t e d by th e dye r a t i o

an d b y t h e t o t a l f e c a l c o l l e c t i o n

22

t e c h n i q u e w o u ld b e p r a c t i c a l l y i d e n t i c a l .

In a stu d y o f th e v a r i a t i o n in

dye c o n c e n t r a t i o n o f f e c e s e x c r e t e d a t d i f f e r e n t ti m e s o f t h e d a y , i t w as
e v i d e n t t h a t t h e n o o n f e c e s h a d a h i g h e r dye c o n c e n t r a t i o n t h a n t h e m o r n ­
i n g o r n i g h t f e c e s w h i c h i n d i c a t e s t h a t a d e q u a t e s a m p l e s s h o u l d be c o l l e c t ­
e d a t d i f f e r e n t t i m e s d u r i n g t h e d a y w h en s © m o lin g b y a p a r t i a l c o l l e c t i o n
te c h n iq u e .
S c h n e i d e r , L u c a s , P a v i e c h and c i p o l l o n i ( 1 6 6 ) p u b l i s h e d e q u a t i o n s f o r
p re d ic tin g th e d ig e stio n c o e ffic ie n ts
and sheep and i n c o n c e n t r a t e s f e d t o

of n u trie n ts
sw in e.

in fe e d s fe d to c a t t l e

They t o o k i n t o a c c o u n t t h e

p e r c e n t a g e s o f s e v e r a l n u t r i e n t s anti, t h e t y p e o f f e e d i n v o l v e d .
w ere p r e s e n t e d f o r e s t i m a t i n g th e d i g e s t i b i l i t y
m a tte r,

crude p r o t e i n ,

c o e f f i c i e n t s f o r o rg a n ic

crude f i b e r , n i t r o g e n - f r e e e x t r a c t ,

and th e c o n t e n t o f t o t a l d i g e s t i b l e
c e n ta g e s o f crude p r o t e i n ,

e th e r e x tra c t,

n u t r i e n t s in fo o d s, u sin g t h e i r p e r ­

crude f i b e r , n i t r o g e n - f r e e e x t r a c t ,

e x tra c t as p re d ic tin g fa c to rs .

E q u a tio n s

and e t h e r

T h eir c a lc u la tio n s in d ic a te d t h a t th e use

o f e q u a t i o n s w i l l r e s u l t i n p r e d i c t i o n e r r o r v a r i a n c e s w h ich a r e
p e r c e n t b elo w th o s e s e c u re d i f

25 t o 4-5

av era g e d i g e s t i o n c o e f f i c i e n t s fro m p r e ­

p a r e d t a b l e s a r e em p lo y ed .
F ra n c o is

( 7 4 ) a l s o p r e s e n t e d f o r m u l a s an d t a b l e s f o r o b t a i n i n g t h e

c o e ffic ie n t of d ig e s tib ility
o f t h e ©mount o f c e l l u l o s e
S ch n eid er e t a l .

(1 6 4 )

o f o r g a n i c m a t t e r en d p r o t e i n

as a f u n c ti o n

i n th e dry m a tte r .
s i m p l i f i e d tlx ; e q u a t i o n f o r m e r l y p r e s e n t e d

(166) to e s tim a te th e d i g e s t i o n c o e f f i c i e n t s o f cru de p r o t e i n ,
n itro g e n -fre e
ib le n u trie n ts
a b le .

e x t r a c t , and e t h e r e x t r o u t and th e

crude f i b e r ,

co n ten t o f t o t a l d ig e s t­

i n f e e d s f o r w h i c h f e w o r no d i g e s t i b i l i t y d a t a a r c a v a i l ­

The e q u a t i o n u s e s t h e p e r c e n t a g e

crude f i b e r , n it r o g e n - f r e e

c o m p o sitio n o f cru d e p r o t e i n ,

e x t r a c t a n d e t h e r e x t r a c t as p r e d i c t i n g f a c t o r s

and t h e a p p r o p r i a t e c o n s t a n t f o r t h e d i g e s t i o n c o e f f i c i e n t b e i n g c a l c u l a t e d .

o*z

Th© a u t h o r s p o i n t o u t t h a t t h i s

e q u a tio n does n o t

g iv e a s p r e c i s e

an

e s t i m a t e o f th © d i g e s t i o n c o e f f i c i e n t a s t h e e q u a t i o n p r e v i o u s l y r e p o r t e d
w h i c h w as d e s i g n e d f o r u s e w i t h f e e d s o n w h ic h s u f f i c i e n t d i g e s t i b i l i t y
d a t a are a v a i l a b l e w ith th e a n im al s p e c ie s d e s ire d *
FACTORS AFFECTING THE DIGESTIBILITY OF ROUGHAGES
E f f e c t o f C ru d e F i b e r o n D i g e s t i b i l i t y
The d e f i n i t i o n o f c r u d e f i b e r

s e t up by H e n n e b e r g a n d S to h m a n n ( 9 1 ) ,

b a s e d o n a m e th o d d e v i s e d b y th e m a n d known a s t h e Weende m e th o d f o r e s t i m ­
a tin g cru d e f i b e r ,

c o n s i s t s o f th e r e s id u e a f t e r t r e a t m e n t w ith 1 ,2 5 p e r ­

cen t s u lfu ric a c id ,

1 , 2 5 p e r c e n t p o t a s s i u m h y d r o x i d e , w a t e r , a l c o h o l and

e t h e r a n d i s e s s e n t i a l l y t h e m e th o d m o s t w i d e l y u s e d t o d a y .

T his i n c l u d e s

a m i x t u r e o f c h e m i c a l s u b s t a n c e s f r o m t h e p l a n t c e l l m em brane w h i c h i s
p rim a rly c e l lu lo s e , h e m ic e llu lo se
as lig n in , c u tin ,

and o t h e r e n c r u s t i n g

r e p r e s e n t th e r e l a t i v e l y in d i g e s tib l e

tio n .

such

s u b e r i n and p e c t i n s .

I t w as o r i g i n a l l y i n t e n d e d t h a t t h e

th e n itr o g e n - f r e e

su b sta n c e s,

crude f i b e r f r a c t i o n

f r a c t io n o f th e

sh o u ld

c a r b o h y d r a te s w h ile

e x t r a c t s h o u l d i n c l u d e t h e m o re r e a d i l y d i g e s t i b l e p o r ­

I t i s now w ^ l l - k n o w n t h a t t h e c r u d e f i b e r f r a c t i o n I s d i g e s t e d t o

a c o n s id e ra b le e x te n t and,
n itro g e n -fre e e x tra c t.
a m o u n ts o f r e l a t i v e l y

in

some cases, t o a, g r e a t e r e x t e n t t h a n t h e

The n i t r o g e n - f r e e e x t r a c t a l s o c o n t a i n s v a r y i n g
in d ig e s tib le

c o n s titu e n ts , in c lu d in g lig n in .

C r a m p to n ( 4 3 ) r e p o r t e d t h a t i n r o u g h a g e s , p a r t i c u l a r l y p a s t u r e s , t h e
c r u d e f i b e r f r a c t i o n i s f r e q u e n t l y m ore d i g e s t i b l e t h a n t h e n i t r o g e n free

e x tra c t.

C r a m p to n and M a y n a rd ( 4 6 ) r e p o r t e d t h e d i g e s t i b i l i t y

co­

e f f i c i e n t s o f c r u d e f i b e r and n i t r o g e n - f r e e e x t r a c t f o r t h r e e c l a s s e s o f
r o u g h a g e s a i d f o r c o n c e n t r a t e s e n d t h e p e r c e n t o f c a s e s i n w h ic h t h e
c ru d e f i b e r w as a s h i g h l y d i g e s t e d as t h e n i t r o g e n - f r e e
d a t a ar© s u m m a r iz e d i n T a b le

2.

e x tra c t.

These

Table 2
A v e r a g e D i g e s t i o n C o e f f i c i e n t s o f F e e d s b y R u m in a n ts
Ho. o f
C ases

K in d o f F e e d

1

% w i t h C ru d e
F ib e r as h ig h
a s 1T.F.E.

G ooff, o f D i g e s t i b i l i t y
C ru d e F i b e r
H .F .E .

110

5 2 .4

5 9 .5

39

P a s t u r e H erbage

12

7 5 .5

7 1 .4

67

S ila g e

25

5 8 .2

6 4 .6

28

C o n c e n tra te s

88

5 3 .3

7 8 .5

10

D ry R o u g h a g e s

■j_
F ro m C r a m p to n a n d M a y n a rd ( 4 6 ) .
A rm sby ( 5 )
lig n in ,

s ta t e d t h a t crude f i b e r

c o n ta in e d m ost o f th e c e l l u l o s e ,

c u t i n , a n d some o f t h e m ore d i f f i c u l t l y

so lu b le h e m ic e llu lo s e s .

H e a d d e n ( 8 9 ) f o u n d t h a t t h e c r u d e f i b e r o f a l f a l f a c u t i n e a r l y b lo o m
s ta g e c o n ta in e d 7 9 .0 p e r c e n t c e l l u l o s e

and 2 1 . 0 p e r c e n t l i g n i n .

R orm an ( 1 5 3 ) c o n c l u d e d t h a t t h e c r u d e f i b e r d e t e r m i n a t i o n i s m i s ­
le a d in g b eca u se th e
s h ip to th e
ta in e d .

f r a c t i o n o b ta in e d docs n o t

s tru c tu ra l

bear any d e f i n i t e

re la tio n ­

c o n s t i t u e n t s o f t h e m a t e r i a l fro m w h ich i t i s o b ­

He r e p o r t e d t h e c e l l u l o s e

and l i g n i n c o n t e n t s o f t h e c r u d e f i b e r

from, s e v e r a l f e e d s an d f o u n d t h a t t n e m ore h i g h l y l i g n i f i e d m a t e r i a l s do
n o t n e c e ssa rily y ie ld

a cru d e f i b e r h ig h i n l i g n i n .

Louw ( 1 1 3 ) made a s t u d y o f t h e d i g e s t i b i l i t y o f t h e v a r i o u s

ce11-

w a l l c o n s t i t u e n t s o f g r a s s e s a s a f f e c t e d by t h e s t a g e o f m a t u r i t y , u s i n g
m a t e r i a l from e a r l i e r d i g e s t i b i l i t y t r i a l s .

The g r a s s

sam p les w ere a

m i x t u r e o f v e l d g r a s s e s grow n i n S o u t h A f r i c a and w e r e c u t a f t e r p e r i o d s
of i

2,

3 a n d 4 m o n th s o f u n d i s t u r b e d

g ro w th .

In th e se

g ra ss m ix tu re s

a n d i n t h e f e c c s f r o m s h e e p c o n s u m i n g th e m a s t h e i r e n t i r e

ra tio n ,

e stim ­

a t i o n s w e r e made o f c e l l u l o s e , l i g n i n , t o t a l f u r f u r a l y i e l u , x y l a n n o m

c e l l u l o s e , u ro n ic a c id a n h y d rid e s , p e n to s a n s , h e m ic e llu lo s c s , c o ld w a te r
so lu b le f r a c t i o n ,

crude p r o te in ,

e th e r e x t r a c t and t o t a l a sh ; as w e ll as

t h e am ount and c o m p o s itio n o f th e c ru d e f i b e r
W i th i n c r e a s i n g m a t u r i t y o f t h e
and t h e r a t i o

I n th e g r a s s and f e c c s .

g r a s s , th e p e rc e n ta g e o f n a tu r a l c e llu lo s e

o f x y l& n t o t r u e c e l l u l o s e

in c re a se d s lig h tly *

i n t h e l i g n i n a n d h e m i c e l l u l o s e c o n t e n t s vmre r e l a t i v e l y
g e stib ility tria ls

show ed t h e t r u e

©nd t h e l i g n i n t h e

le a s t d ig e stib le

a l l th e

c o n stitu e n ts

c e llu lo s e to

The i n c r e a s e

sm a ll.

The d i ­

be t h e m o s t d i g e s t i b l e

o f t h e c e 11- w a l l c o n s t i t u e n t s , b u t

showed d e c r e a s i n g d i g e s t i b i l i t y w i t h a d v a n c i n g ma­

tu rity .

The d i g e s t i b i l i t y o f t h e h e m i c e l l u l o s e s l a y b e t w e e n t h e v a l u e s

fo r tru e

c e l l u l o s e and l i g n i n ,

c e llu lo se .
th e fe c e s

b e in g c o n s id e r a b ly lo w er th a n t h a t o f t r u e

E x a - m in a t io n o f t h e c r u d e f i b e r i s o l a t e d f r o m t h e g r a s s o r f r o m
showed t h a t t h e m a t e r i a l fro m g r a s s c o n t a i n e d a n a v e r a g e o f 9 6 . 5

p ercen t n a tu ra l c e llu lo se ,

th e

re m a in d e r c o n s i s t i n g m o s tly o f l i g n i n .

m a t e r i a l i s o l a t e d fro m f e c e s c o n ta in e d 9 2 .8 p e r c e n t n a t u r a l c e l l u l o s e
about

10

p ercen t lig n in .

I t is

to th e re a g e n ts

u s e d i n t h e Weende m e th o d f o r e s t i m a t i n g c r u d e f i b e r and t h e r e f o r e
a m o u n ts o f t h e s e c o n s t i t u e n t s r e c o v e r e d i n t h e c r u d e f i b e r
From

86

to

and

e v id e n t fro m t h e i r d a t a t h a t th e v a r io u s

c o n s t i t u e n t s o f t h e c e l 1 - w a l l show ed a v a r y i n g r e s i s t a n c e

sid e ra b le v a r ia tio n .

The

93 p e r c e n t o f t h e t r u e

40 p e r c e n t of t h e x y l a n i n c e l l u l o s e , 12 t o

th e

show ed c o n ­

c e llu lo se ,

33 t o

15 p e r c e n t o f t h e l i g n i n a n d

o n ly a b o u t 1 to 4 p e r c e n t o f t h e p e n to s a n i n h e m i c e l l u l o s e w ere r e c o v e r e d .
C o m p a riso n s by v a r i o u s i n v e s t i g a t o r s o n t h e e f f e c t o f th e c o n t e n t o f
cru d e f i b e r on th e d i g e s t i b i l i t y

o f ro u g h ag es m ust ta k e I n to c o n s i d e r a t i o n

t h a t d i f f e r e n t a n a l y t i c a l m e th o d s f o r c ru d e f i b e r g iv e w i d e l y d i f f e r e n t
re s u lts.
th a t th re e

T h i s h a s b e e n p o i n t e d o u t by j j o r d f e l d t e t a l .

( 1 3 2 ) who show ed

d i f f e r e n t m e th o d s f o r th e d e t e r m i n a t i o n o f c ru d e f i b e r gave

e f f e c t o f c r u d e f i b e r c o n t e n t o n d i g e s t i b i l i t y may be e x p r e s s e d b y t h e
e q u a t i o n , Y = 9 0 . 1 - 0 .8 9 7 X , whe r e
Y - d i g e s t i b i l i t y o f th e d ry m a tte r

and

X * crude f i b e r c o n te n t o f th e fe e d .
D u ckw o rth (5 7 ) fo u n d a c l o s e n e g a t i v e c o r r e l a t i o n b etw een th e
fib e r

c o n t e n t and t h e d i g e s t i b i l i t y

c o e f f ic ie n ts of roughages.

(5 3 ) h as c a l c u l a t e d fo rm u la s f o r e s tim a tin g th e
a rtific ia lly

D ijk stra

s ta rc h e q u iv a le n t of

d r i e d g r a s s from th e p e r c e n ta g e s o f c ru d e p r o t e i n and c ru d e

f i b e r or from th e crude f i b e r a lo n s .
b etw een th e

crude

crude f i b e r

Eomb ( 9 2 ) f o u n d a c l o s e c o r r e l a t i o n

c o n t e n t and d i g e s t i b i l i t y .

Tifith h a y s and s i l a g e ,

t h e r e l a t i o n b etw ee n l i g n i n c o n t e n t and d i g e s t i b i l i t y

seem e d m o re m a r k e d

th a n b etw ee n c ru d e f i b e r and d i g e s t i b i l i t y .
H a lls w o rth (8 5 ) used th e p u b lis h e d r e s u l t s of d i g e s t i b i l i t y t r i a l s
by o th e r w o rk ers to

sh o w a l i n e a r r e l a t i o n b e t w e e n t h e p e r c e n t a g e o f c r u d e

f i b e r an d t h e d i g e s t i b i l i t y o f t h e o r g a n i c m a t t e r o f f e e d i n g
l i n e a r r e l a t i o n was a l s o

e s t a b l i s h e d betw een th e

t u r e h e r b a g e and t h e c r u d e f i b e r c o n t e n t .

0

X

A

sta rc h e q u iv a le n t of p a s ­

T he r e l a t i o n b e t w e e n s t a r c h c -

q u i v a l e n t a n d c r u d e f i b e r f o r a w id e r a n g e o f p a s t u r e
c o n te n ts co u ld

stu ffs.

be e x p r e s s e d b y t h e e q u a t i o n ,

s p e c ie s and f i b e r

S ta r c h E q u i v a l e n t - 7 3 .5 6 -

. 62X, w h e r e
th e p e rc e n ta g e o f cru d e f i b e r .

S i m i l a r r e s u l t s vie r e r e p o r t e d b y J a r l

(9 8 , 100) u s in g th e

p re v io u s ly

t o c o m p a re t h e f i b e r

co n d u cted d i g e s t i o n t r i a l s

hays w ith th e d i g e s t i b i l i t i e s .

re su lts of
co n ten t o f

He f o u n d a n e g a t i v e c o r r e l a t i o n b e t w e e n

t h e f i b e r c o n t e n t and t h e d i g e s t i b i l i t i e s

o f th e h a y s .

Axe I s s o n ( 1 1 , 1 2 ,

1 3 , 1 4 ) a n d A x e l s s o n and E r i k s s o n ( 1 5 ) r e p o r t e d t h a t t h e c r u d e f i b e r c o n ­
t e n t o f r o u g h a g e s show s a h i g h n e g a t i v e

c o r r e l a t i o n w ith th e d ry m a tte r

28

d ig e stib iliiy ,

A x e ls s o n ( 1 3 , 14) co m p ile d th e d a t a from 757 d i g e s t i o n

t r i a l s made i n d i f f e r e n t p a r t s o f t h e Y /orld a n d c o m p a r e d t h e d i g e s t i b i l i t y
c o e f f i c i e n t s o f crude p r o t e i n , e t h e r e x t r a c t , n itr o g e n - f r e e
f i b e r and o r g a n i c m a t t e r t o
a lfa lfa ,

th e

crude f i b e r

e x tra c t,

crude

c o n te n t o f th e d ry m a tte r of

c l o v e r , c l o v e r - t i m o t h y m i x t u r e s and t i m o t h y f e d g r e e n , a s s i l a g e

o r a s hay*

T he c r u d e f i b e r c o n t e n t i n f l u e n c e d t h e d i g e s t i b i l i t y o f a l l t h e

n u t r i e n t s , t h a t o f th e o r g a n i c m a t t e r d e c r e a s in g by 0 .7 1 f o r e a c h in c r e a s e
o f one p e r c e n t i n c r u d e f i b e r
N o rd fe ld t e t a l .

c o n te n t.

(1 3 2 ) i n v e s t i g a t e d th e e f f e c t o f l i g n i n ,

p e n t o s a n s an d c r u d e f i b e r

on th e d i g e s t i b i l i t y

c e llu lo se ,

of th e dry m a tte r o f th e

r a t i o n and f o u n d t h a t c r u d e f i b e r w as a s c l o s e l y c o r r e l a t e d w i t h d i g e s t i b i l ­
ity

o f t h e d r y m a tte r a s any of th e

u lo se

c o n stitu e n ts

stu d ie d .

I f lig n in ,

a n d p e n t o s a n s w e r e d e t e r m i n e d s e p a r a t e l y and t h e i r t o t a l

upon th e d i g e s t i b i l i t y

c a l c u la te d by p a r t i a l

c e ll­

in flu e n c e

r e g r e s s io n , th e d i g e s t i b i l i t y

o f t h e d r y m a t t e r was f o u n d t o h a v e l e s s d e v i a t i o n a r o u n d t h e l i n e o f
r e g r e s s i o n t h a n w hen c a l c u l a t e d f r o m c r u d e f i b o r a l o n e .
T here i s

c o n s i d e r a b l e e v i d e n c e t h a t t h e o p tim u m f i b e r c o n t e n t o f t h e

d i e t v a r i e s w i t h t h e s p e c i e s o f a n i m a l , t h e t y p e o f r a t i o n f e d and. o t h e r
e n v iro n m e n ta l f a c t o r s .

A xeIsson ( 8 , 9 ,

10) h a s p r o p o s e d t h a t a c e r t a i n

o p tim u m l e v e l o f f i b e r i s n e e d e d i n a r a t i o n i f t h e e n e r g y i s t o be u t i l i z e d
m ost e f f i c i e n t l y .
t w e e n 18 t o

He b e l i e v e s t h e o p tim u m l e v e l o f c r u d e f i b e r t o be b e ­

23 p e r c e n t a n d p o i n t s o u t t h a t i n d i g e s t i b i l i t y

v a lu e s a r e o b ta in e d by d i f f e r e n c e ,
th e

i t i s d e s i r a b l e t h a t b o th th e b a s a l and

su p p le m e n ta ry r a t i o n s c o n ta in th e

A x e lsso n (1 3 ) h as a ls o
c a ttle

t r i a l s w here

op tim um a m o u n ts o f p r o t e i n a n d f i b e r .

c o m p a re d t h e r e l a t i v e

a b i l i t i e s o f th e p ig , h o rs e ,

a n d s h e e p t o d i g e s t t h e o r g a n i c m a t t e r o f t h e r a t i o n a n d show ed t h a t

w ith sheep and c a t t l e

th e d i g e s t i b i l i t y f e l l as th e crude f i b e r in c re a s e d

29

i n 't h e d i e t .
an d t h e

Th© r e l a t i o n "betw een t h e d i g e s t a b i l i t y o f t h e o r g a n i c m a t t e r

c o n te n t of crude f ib e r in th e r a tio n o f c a t t l e

and s h e e p i s

show n

by t h e e q u a t i o n , Y ~ 87*8 - 0 . 8 3 X , w h e r e Y i s t h e d i g e s t i b i l i t y o f t h e
o rg a n ic m a tte r and X i s th e p e rc e n ta g e o f cru d e f i b e r in th e d i e t .
N o r d f e l d t je t a l . (1 3 1 ) c o n d u c te d a f e e d i n g e x p e rim e n t w i t h d i f f e r e n t
l e v e l s o f c r u d e f i b e r i n t h e r a t i o n o f d a i r y cow s.
ra tio n

O t h e r c o m p o n e n ts o f t h e

( d i g e s t i b l e p r o t e i n and t o t a l d i g e s t i b l e n u t r i e n t s )

s ta n t.

w e re k e p t c o n ­

F o u r d i f f e r e n t r a t i o n s w e r e f e d , a s f o l l o w s ; A w i t h 60 p o u n d s o f

N a p i e r g r a s s , B w i t h 40 p o u n d s o f N a p i e r g r a s s , C w i t h 20 p o u n d s o f N a p i e r
g r a s s d a i l y p e r cow a n d D w i t h n o N a p i e r g r a s s .

The n e c e s s a r y a m o u n ts o f

p r o t e i n a n d t o t a l d i g e s t i b l e n u t r i e n t s w e r e made u p w i t h p i n e a p p l e b r a n ,
s o y b e a n o i l m e a l , m e a t m e a l , f i s h m e a l an d m o l a s s e s .

The c r u d e f i b e r

te n t o f th e se fo u r ra tio n s

i n p e r c e n t a g e o f d r y m a t t e r w as a s f o l l o w s ;

A , 2 2 . 7* B, 1 9 . 6 j C, 1 6 . l j

a n d D, 1 2 . 0 p e r c e n t .

o f cru d e f i b e r in th e
l/7hen t h e

con­

The e f f e c t o f t h e l e v e l

f e e d u p o n m i l k p r o d u c t i o n w as h i g h l y s i g n i f i c a n t .

c r u d e f i b e r c o n t e n t o f t h e f e e d w as i n c r e a s e d a b o v e 16 p e r c e n t ,

a drop i n m ilk p r o d u c tio n o c c u rre d .

The a v e r a g e d a i l y 4 p e r c e n t f a t

c o r r e c t e d m i l k p r o d u c t i o n p e r cow f o r

12

w e e k s w as

2 0 .6

p o u n d s on r a t i o n

A, 2 1 . 7 p o u n d s o n r a t i o n B, 2 3 . 4 p o u n d s o n r a t i o n C, a n d 2 3 . 8 p o u n d s o n
r a t i o n D*

M ie th e r o t h e r c o m b in a tio n s o f f e e d s m ig h t have a d i f f e r e n t

o p tim u m l e v e l o f c r u d e f i b e r i n t h e
L a n c a s te r (11)

r a t i o n h a s n o t b e e n shown.

g a v e a n a l y t i c a l an d d i g e s t i b i l i t y

l e n t f e e d s and s i x r o u g h a g e s .

L ig n in , c e llu lo s e

d a t a f o r 11 s u c c u ­

and c r u d e f i b e r a l l h a d

a d e p r e s s i n g e f f e c t u p o n t h e d i g e s t i b i l i t y o f o r g a n i c m a t t e r a s show n b y
th e

c o r r e l a t i o n c o e f f i c i e n t s o f - 0 , 9 7 8 , - 0 . 8 0 8 and - 0 . 9 4 4 f o r t h e

d ig e st­

ib ilitie s

o f t h e o r g a n i c m a t t e r and t h e p e r c e n t a g e c o n t e n t o f l i g n i n ,

c e llu lo se

and c r u d e f i b e r ,

re sp e c tiv e ly .

SO

McMeekan ( 1 2 3 ) a l s o c a l c u l a t e d

a c o r r e l a t i o n c o e f f i c i e n t o f -0*944

b e tw e e n th e c ru d e f i b e r c o n t e n t and t h e d i g e s t i b i l i t y o f th e o r g a n i c
m a t t e r o f f e e d s r e p o r t e d b y Woodman ( 1 8 7 ) w h i c h i s i d e n t i c a l w i t h t h e
c o r r e l a t i o n c o e f f i c i e n t r e p o r t e d by L a n c a s te r (1 1 0 ),
P h i l l i p s a n d L o u g h lin . ( 1 5 1 ) a n a l y z e d 25 s a m p l e s o f e s s e n t i a l l y p u r e
s ta n d s o f fo ra g e fro m v a r io u s l a b o r a t o r i e s i n th e U n ite d S t a t e s t h a t had
serv ed as th e s o le r a t i o n in fe e d in g ex p erim en ts w ith c a t t l e .
p ro te in ,

The l i g n i n ,

c e l l u l o s e and c r u d e f i b e r c o n t e n t s o f t h e s a m p l e s w e r e a l l m ore

o r l e s s c lo s e ly r e l a t e d to t h e i r y ie ld o f e n erg y , b u t a t d i f f e r e n t le v e ls
o f t h e s e c o n s t i t u e n t s f o r tim o th y and a l f a l f a ,

Y /ith in a s p e c i e s , c ru d e

f i b e r w as l e s s c l o s e l y c o r r e l a t e d w ith d i g e s t i b i l i t y o f e n e r g y and d r y
m sL tter t h a n was t h e l i g n i n c o n t e n t ,
S t e e n s b e r g and W in th e r (1 7 5 ) c o n d u c te d d i g e s t i b i l i t y t r i a l s w i t h
l u c e r n ta k e n a t e a r l y , norm al and l a t e f i r s t c u t t i n g s .

The l a t e r c u t t i n g s

i n c r e a s e d i n c ru d e f i b e r c o n t e n t and th e d i g e s t i b i l i t y o f t h e o r g a n i c
m a tte r d e c re a se d ,
S o t o l a (1 7 1 ) d id n o t g e t a c o n s i s t e n t r e l a t i o n b etw een th e c ru d e
f i b e r c o n t e n t o f w h e a t, o a t s and b a r l e y h a y s and d i g e s t i b i l i t y o f th e
v a rio u s n u tr i e n ts w ith in c re a s in g m a tu rity .

T h is stu d y in c lu d e d r ip e

g r a i n s w h ic h p r o d u c e d a n i n c r e a s e d c ru d e f i b e r c o n t e n t o f t h e stem s co n ­
c o m ita n t w ith in c r e a s e s
m a tu rin g h e a d s.

in th e r e a d ily d ig e ste d ca rb o h y d ra te s o f th e

The r e l a t i o n s h i p b e t w e e n t h e d i g e s t i b i l i t y o f t h e d r y

m a t t e r a n d t h e c r u d e f i b e r c o n t e n t o f th© s t e m s a n d l e a v e s o n l y w o u ld
l i k e l y g iv e c o n s i s t e n t r e s u l t s .
tia te d

T h is a ssu m p tio n i s p a r t i a l l y

su b stan ­

b y l a t e r w ork b y S o t o l a (1 7 3 ) w ith d i g e s t i b i l i t y s t u d i e s o f t h r e e

s t a g e s o f s m o o th b r o m e g r a s s .

C ru d e f i b e r i n c r e a s e d f r o m 1 9 , 7 7 t o

p e r c e n t w h ile t h e p l a n t grew from 4 , 5 t o

36 i n c h e s i n h e i g h t .

3 5 .9 2

The d r y

31

m a t t e r w as 81 p e r c e n t d i g e s t i b l e

a t t h e 4 * 5 - i n c h s t a g e and o n l y 5 5 , 8 p e r c e n t

d i g e s t i b l e a t t h e 3 6 -in c h sta g e *
S w i f t ejb a l * ( 1 7 8 ) c o n d u c t e d

d ig e stib ility

t r i a l s w i t h la m b s and s h e e p

f e d a b a s a l d i e t o f g ood q u a l i t y o f a l f a l f a a n d t i m o t h y h a y , c o r n m e a l a n d
l i n s e e d cake m e a l,

w hen c r u d e f i b e r

added, th e d i g e s t i b i l i t y

s u p p l e m e n t s i n th© f o r m o f s t r a w w e re

c o e f f ic ie n ts o f th e p r o te i n , e th e r e x t r a c t ,

cru d e

f i b e r a n d e n e r g y o f t h e w h o l e r a t i o n d e c r e a s e d an d t h e t o t a l a m o u n t o f p r o ­
t e i n an d e t h e r e x t r a c t d i g e s t e d w as r e d u c e d .
F o r b e s an d G a r r i g p s
ste e rs

(7 0 ) fo u n d c o r r e l a t i o n

c o e f f i c ie n t s o f -0 .7 4 f o r

and - 0 . 6 4 f o r w e t h e r s b e t w e e n t h e d i g e s t i b i l i t y o f t h e o r g a n i c m a t t e r

and t h e c r u d e f i b e r c o n t e n t o f g ra z e d f o r a g e s .

The b e s t c o r r e l a t i o n b e t w e e n

c h e m i c a l c o m p o s i t i o n a n d o r g a n i c m a t t e r d i g e s t i b i l i t y was o b t a i n e d w i t h
lig n in *
R eid (1 5 3 ) r e c e n t l y r e p o r te d

a c o rre la tio n

c o e f f i c i e n t o f + 0 .8 8 5 b e tw e e n

th© c r u d e f i b e r c o n t e n t a n d t h e t o t a l d i g e s t i b l e n u t r i e n t s

c o n te n t o f th e

grass.
C ru m p to n an d J a c k s o n ( 4 4 ) d i d n o t f i n d t h e c r u d e f i b e r c o n t e n t o f
p a s t u r e h e r b a g e t o be c l o s e l y c o r r e l a t e d t o
g e stib ility

s e a s o n a l changes i n th e d i ­

o f th e s e fo rag es*

A c o m p ila tio n o f th e r e g r e s s i o n e q u a tio n s r e l a t i n g th e crude f i b e r con­
t e n t o f a fe e d to th e d i g e s t i b i l i t y o f th e d ry m a tte r i s

g iv e n i n T ab le 3.

7 n

T ab le 3 .
R e g re ssio n e q u a tio n s r e l a t i n g d i g e s t i b i l i t y
m a tte r to

R e g re ssio n E q u a tio n

Y = 1 3 0 .3 -

cru d e f i b e r c o n te n t o f r a t i o n

M a te ria l

i
i
o
»
03
^ '

C o r r e 1.
C o eff.

Y = 8 3 . 0 - 0 .7 0 X

A lfa lfa

-0 .8 4 2

2,.14-X

o f dry

v ^ 8 7 .8 - 0 .8 3 X

-----

Y = 8 6 . 4 - 0 .8 4 X

-0 .9 7

Y = 9 0 .1 - 0 .8 97 X

R eference

P h i l l i p s I L o u g h lin (151)
i)

T im o th y

ii

tt

A x e lsso n ( 1 5 ) .
H o rd fe ld t (1 3 2 ).
O lo fsso n (1 4 0 ).

—-

--

Y * 96 - 1 . 0 0 X

-0 .7 4

p a stu re
(S te e rs)

F o r b e s and
G a rrig u s (7 0 ).

Y = 94 - 1 . 0 1 X

-0 .6 4

P a stu re
( b o th e rs)

F o rb e s and
G a rrig u s (7 0 ).

E f f e c t o f C e l l u l ose C o n te n t on D i g e s t i b i l i t y
C e l l u l o s e c o m p r i s e s s u c h a l a r g o am o u n t o f t h e
m ost fo ra g e s t h a t i t s

a v a ila b ility

t o t h o a n i m a l an d i t s e f f e c t o n t h e d i ­

g e s t i b i l i t y o f th e o th e r fe e d c o n s t i t u e n t s
p e c ia lly

i n ru m in an t n u t r i t i o n *

on t h e r e l a t i o n o f c e l l u l o s e

t o t a l dry n a t t e r o f

i s o f m a jo r im p o r ta n c e a e s ­

A lth o u g h t h e r e i s

p.

p a u c ity

in f o r a g e s to t h e i r n u t r i t i v e

s e v e r a l r e p o r t s v rh ic b i n d i c a t e t h a t

o f in fo rm a tio n

v a lu e , th e re are

th e e s t i m a t i o n o f c e l l u l o s e , l i g n i n ,

h e i f i i c c l l u l o s e s and o t h e r c a r b o h y d r a t e s -rov.ld Oi v o a b e t t e r

in d ic a tio n of

f o r a g e v a l u e t h a n a d o t e r m i n a t i o n o f t h o c r u d e f i b e r c o n t o r t end c a l c u l a ­
t i o n o f t h e am ount o f n i t r o g e n - f r e e e x t r a c t .
161).

(ef,

C2, 1 0 1 , 1 1 7 , 1 3 3 , I d ,

33

T ru e c e l l u l o s e

i n a ch e m ic a l sen se i s & g lu c o se p o ly s a c c h a r id e y i e l d ­

in g o n ly g lu c o se on h y d r o ly s is .
v ery c lo se

C e l l u l o s e i s form ed i n m o st p l a n t s i n

a s s o c i a t i o n w i t h o t h e r p o l y s a c c a r i d e s and h a s h e x o s a n s and

p e n t o s a n s i n t e r m i x e d i n th e c e l l u l o s e f i b e r s w h ic h fo rm a norm al p a r t o f
th e c e l l u l o s i c s tr u c t u r e *
w ith th e tr u e c e l lu lo s e ,
t a i n e d \u ith th e t r u e
a n d N orm an ( 8 8 )*

These s u b s ta n c e s t h a t a r e c l o s e l y a s s o c i a t e d
and u n d e r some c o n d i t i o n s a r e e x t r a c t e d and r e ­

c e l l u l o s e , h a v e b e e n c a l l e d t h e c e l l u l o s a n s b y H aw ley

N orm an ( 1 3 5 ) b e l i e v e s t h a t t h e c e l l u l o s a n s a r e l a i d down

w ith th e c e llu lo s e as i t i s
fib e rs*

f o r m e d and t h e tw o f o r m t h e m i c e l l a e o f t h e

The m o l e c u l a r s i z e o f t h e c e l l u l o s a n s i s c o n s i d e r a b l y l e s s t h a n

th a t o f tru e c e llu lo s e .

The s u g a r u n i t s a r e j o i n e d b y s e c o n d a r y v a l e n c i e s

w eaker th a n th o s e j o i n in g th e tr u e
le n g th i s

c e l l u l o s e u n i t s and s in c e th e c h a i n

s h o r t e r , t h e y may be l a r g e l y e x t r a c t e d u n d e r c o n d i t i o n s w h i c h

do n o t e x t r a c t t h e t r u e c e l l u l o s e *
u n lik e ly th a t c e llu lo s e

N orman an d F u l l e r ( 1 3 8 ) b e l i e v e i t

e n d t h e a s s o c i a t e d p o l y u r o n i d e h e m i c e l l u l o s e s an d

l i g n i n a r e c h e m i c a l l y l i n k e d o r t h a t s o - c a l l e d "c o m p o u n d ” c e l l u l o s e s o c c u r ,
b u t t h a t th e norm al s t r u c t u r e i s

su ch t h a t i n t e r p e n e t r a t i n g sy stem s a r e

found.
The n u t r i t i v e v a l u e o f c e l l u l o s e

i s i n d i c a t e d b y Woodman an d S t e w a r t

( 1 9 0 ) who r e p o r t e d t h a t o v e r 90 p e r c e n t o f t h e d i g e s t i b l e
a v a i l a b l e i n t h e form o f g lu c o s e and o n ly a b o u t
t a t i o n to

g a s o s and o r g a n i c a c id s *

8

c e l l u l o s e becom es

p e r c e n t im d e rg o e s fe rm e n ­

C e l lu lo s e i s a t t a c k e d by v a r i o u s

b a c t e r i a t h a t fo rm e x t r a c e l l u l a r enzym es t h a t a t t a c k t h e c e l l u l o s e m o le ­
cu le*

B o th a e r o b e s an d a n a e r o b e s a r e know n t o b e c a p a b l e o f d e c o m p o s i n g

o r are even dependent on c e l lu lo s e

(9 4 , 121, 1 3 8 ).

Woodman a n d S t e w a r t

(1 9 1 ) s tu d ie d th e b a c t e r i a l d e c o m p o s itio n o f th e crude f i b e r i s o l a t e d
fro m v a r io u s fe e d s and found th e f e r m e n ta tio n c o e f f i c i e n t s i n a l l

cases

34

h i g h e r t h a n t h e d i g e s t i o n c o e f f i c i e n t s d e t e r m i n e d i n anim & l t r i a l s .

A lso ,

t n e c r u d e f i b e r f e r m e n t a t i o n c o e f f i c i e n t s f o r t h e u n t r e a t e d f e e d s w e r e much
lo w e r t h a n t h e c o r r e s p o n d in g v a l u e o b ta in e d fro m t h e s e p a r a t e d f i b e r .

Ih is

w o u ld i n d i c a t e t h a t a s s o c i a t i o n o f t h e c e l l u l o s e w i t h o t h e r e n c r u s t i n g e e l l w a l l c o n s t i t u e n t s i n p l a n t m a t e r i a l s w o u ld b e a l i m i t i n g f a c t o r i n t h e
c e l l u l o s e u t i l i z a t i o n by th e a n im a l.

Woodman ( 1 8 7 ) a l s o

re p o rte d

011

th e

d i f f e r e n c e i n t h e d i g e s t i b i l i t y o f l i g n i f i e d and n o n - l i g n i f i e d f e e d i n g
stu ffs.

N o n l i g n i f i e d f e e d s such a s s u g a r b e e t p u l p , m a n g o ld s, cabbage and

s u g a r b e e t t o p s show ed c o e f f i c i e n t s o f d i g e s t i b i l i t y o f t h e c e l l u l o s e
8 9 .7 , 7 8 . 0 , 7 4 .0 and 7 1 .6 p e r c e n t ,

re sp e c tiv e ly .

as

The c o e f f i c i e n t s o f d i ­

g e s t i b i l i t y o f th e c e l l u l o s e o f such l i g n i f i e d fe e d s as o a t s tra w , w h eat
s t r a w , c o t t o n s e e d m e a l , l i n s e e d m e a l an d w h e a t b r a n w e r e o n l y 5 4 . 0 ,

5 0 .0 ,

3 7 . 0 and 2 6 . 0 p e r c e n t , r e s p e c t i v e l y .
H aum ann ( 1 2 8 ) made a s t u d y o f t h e c r u d e f i b e r f r a c t i o n s f r o m r a t i o n s
u s e d i n s e v e r a l d i g e s t i b i l i t y t r i a l s w i t h s h e e p an d o f t h e c o r r e s p o n d i n g
feces.

The d i g e s t i b i l i t y o f t h e c r u d e f i b e r a n d i t s p e n t o s a n a n d c e l l u l o s e

c o m p o n e n ts sh ow ed w id e v a r i a t i o n w i t h d i f f e r e n t f e e d s an d w a s i n v e r s e l y
p r o p o r t i o n a l t o t h e l i g n i n c o n t e n t , w h ic h was i n d i g e s t i b l e i n n e a r l y a l l
cases.

C r a m p to n

and

M a y n a rd ( 4 6 ) r e p o r t e d f e e d c e l l u l o s e t o be 6 2 . 5 p e r ­

c e n t d i g e s t e d b y a s t e e r on e q u a l p a r t s o f a l f a l f a

an d g r a i n .

b o h y d r a t e s c a l c u l a t e d b y d i f f e r e n c e w e re 9 4 . 8 p e r c e n t d i g e s t e d .

O th e r c a r ­
R eid (153)

re p o rte d th e d ig e s tio n c o e f f ic ie n ts o f

c e l l u l o s e f r o m e a r l y , m edium a n d

l a t e - c u t g ra s s as 7 7 .8 ,

re sp e c tiv e ly .

6 8 .5 and 6 1 . 0 ,

o ccu rred in th e d i g e s t i b i l i t y

o f th e d ry m a tte r.

The c e l l u l o s e c o n t e n t o f g r a s s e s ,
d ry m a tte r o r of

th e

le g u m e s; t h u s g iv in g

( 6 ).

S im ila r d ecre ase s

e x p ressed as a p e rc e n ta g e o f

th e

c a r b o h y d r a t e f r a c t i o n , i s much h i g h e r t h a n t h a t o f
h i g h e r c r u d e f i b e r c o n t e n t s i n g r a s s e s t h a n i n le g u m e s

35

Much o f th© r e p o r t e d w ork o n t h e d i g e s t i b i l i t y o f c e l l u l o s e may h a v e
been in flu e n c e d by o th e r f a c to r s i n th e r a t i o n a f f e c tin g d i g e s t i b i l i t y ,
R e c e n t w o rk h a s shown, t h a t t h e d i g e s t i o n o f r o u g h a g e b y c a t t l e w a s i n ­
c re a se d by a d d itio n o f p r o t e i n ,

(31,

3 4 , 3 6 ) a n d a l s o by a w a t e r e x t r a c t

o f a l f a l f a h ay and t h e a s h fro m good q u a l i t y a l f a l f a h a y ( 33) .
B urroughs e t a l .

( 3 0 ) h a v e r e c e n t l y r e p o r t e d a n a r t i f i c i a l rum en

te c h n iq u e f o r stu d y in g c e l l u l o s e d i g e s t i o n i n ro u g h ag es.
n iq u e ,

B urroughs e t a l .

ab le n itr o g e n ,

(35)

U sin g t h i s t e c h ­

s tu d ie d th e e f f e c t o f su p p lem en ts o f a v a i l ­

a c o m p le x m i n e r a l m i x t u r e an d a n a u t o c l a v e d e x t r a c t o f

cow m a n u re o n t h e d i g e s t i o n o f f o u r p o o r q u a l i t y r o u g h a g e s ( c o r n ,
w h e a t s t r a w , c o r n c o b s , and m a tu re t i m o th y - b l u e

sto v e r,

g r a s s h a y ) an d f o u r good

q u a l i t y d e h y d r a t e d f o r a g e s ( c l o v e r h a y , r y e h a y a n d two l o t s o f a l f a l f a
hay ).

The c e l l u l o s e i n t h o

good q u a l i t y r o u g h a g e s w as d i g e s t e d e f f i ­

c i e n t l y w i t h o u t s u p p l e m e n t a t i o n , w i t h no i n c r e a s e d d i g e s t i o n o c c u r r i n g
whfemi t h e c o m p le x m i n e r a l s a n d a u t o c l a v e d m a n u re e x t r a c t w e r e i n c l u d e d .
The c e l l u l o s e i n t h e p o o r q u a l i t y r o u g h a g e s w as n o t d i g e s t e d e f f i c i e n t l y
w ith o u t s u p p le m e n ta tio n .

The a d d i t i o n o f c o m p le x m i n e r a l s , m a n u re e x t r a c t

o r a v a ila b le n itro g e n g r e a tly in c re a s e d th e d ig e s tio n o f c e llu lo s e

in th e se

poor q u a lity roughages.
B u rroughs e t a l .

(36) a lso

s tu d ie d th e e f f e c t of s e v e r a l c e r e a l

g r a i n s an d p r o t e i n - r i c h f o o d s w i t h r e s p e c t t o t h e i r a b i l i t y
th e d ig e s tio n o f c e llu lo s e
th a t d rie d d i s t i l l e r s
th e

by rum en m i c r o o r g a n i s m s .

s o lu b le s,

to

in c re a se

T h eir r e s u l t s

show ed

so y b ean o i l m eal and l i n s e e d o i l m eal gave

g r e a t e s t i n c r e a s e i n roughage d i g e s t i o n .

Cane m o l a s s e s ,

corn, w heat

b r a n and c o t t o n s e e d m e a l h a d l e s s e f f e c t and. m e a t s c r a p s , f i s h m e a l , l i v e r
m e a l and o a t s had l i t t l e

o r no i n f l u e n c e on r o u g h a g e d i g e s t i o n b y m i c r o ­

o r g a n i s m s i n t h o a r t i f i c i a l ru m e n .

E f f e c t o f L i g n in C o n te n t on D i g e s t i b i l i t y
L i g n in h a s b e e n q u i t e w id e ly s t u d i e d i n f o r a g e p l a n t s and i s
l o g i c a l l y a s s o c ia te d w ith th e d i g e s t i b i l i t y
sin c e i t

is

q u ite

o f th e o th e r feed c o n s titu e n ts

g e n e r a l l y c o n s i d e r e d a s a b i o l o g i c a l l y i n e r t c o n s t i t u e n t w h ic h

i n c r e a s e s w ith a d v a n c in g m a tu r it y o f th e p l a n t ,

( 6 , 46, 134, 148, 159,

1 91).
An i n c r e a s e i n t h e l i g n i n c o n t e n t o f p l a n t m a t e r i a l i s u s u a l l y a s s o ­
c ia te d w ith a d ecrease in i t s

d ig e stib ility

(1 8 , 43, 4 6 , 69, 110, 119, 120,

141, 176, 18 7 ).
L i g n i n h a s b e e n r e p o r t e d t o be i n d i g e s t i b l e b y s t e e r s

(4 -6 ); b y co'ws

o n a l f a l f a h a y ( 8 4 ) ; b y s h e e p ( 8 3 ) ; b y cow s o n a m ix e d f e e d an d b y s h e e p
on d r i e d Sudan g r a s s

( 6 2 ) ; try s h e e p o n m i x e d f e e d s ( 1 7 8 ) ; by s h e e p o n

c l o v e r - t i m o t h y h ay ( 6 8 ) ; by sh eep on K orean le s p e d e z a h a y c u t a t f o u r
s t a g e s o f m a t u r i t y ( 4 1 ) ; by. cow s o n a r a t i o n o f a l f a l f a
s ila g e

and g r a i n a n d a l s o on a r a t i o n o f a l f a l f a h a y ,

sila g e ,

co rn

corn s ila g e

an d

g ra in (1 0 3 ).
Csohka, P h i l l i p s

a n d J o n e s ( 4 8 ) f e l t t h a t l i g n i n 'was dome t h o x y l a t e d

o r t h a t d e g r a d a tio n o f l i g n i n o c c u rre d i n th e

ru m in an t d i g e s t i v e

tra c t

s i n c e d e t e r m i n a t i o n s o f t h e m e t h o x y l g r o u p o n t h e l i g n i n f e d and t h a t
e lim in a te d in th e

feces in d ic a te d th a t lig n in lo s t

m e th o x y l g ro u p s i n p a s s i n g th r o u g h th e a n im a l body.
fe d to

cows a n i n c r e a s e

a p o r tio n o f th e
Tilhen l i g n i n w a s

i n b e n z o i c a c i d e l i m i n a t i o n i n t h e u r i n e w as

o b s e r v e d w h ic h w as b e l i e v e d t o b e d e r i v e d f r o m l i g n i n d e g r a d a t i o n p r o ­
d u c ts.

p a z u r a n d D^Long ( 1 4 5 ) d e t e r m i n e d t h e h i p p u r i c and b e n z o i c a c i d

e x c r e tio n o f sheep fe d c lo v e r h a y c u t a t f iv e

s t a g e s o f m a t u r i t y and

f o u n d t h a t a b o u t t h r e e t i m e s a s m uch h i p p u r i c a c i d w as e x c r e t e d b y t h o
s h e e p f e d th© e a r l y - c u t c l o v e r a s b y t h e

sh e e p f e d th e m a tu re c l o v e r .

37

Since th ey f e l t th a t th e se were e x c r e to r y products o f l ig n in breakdown, i t
in d ic a te d a greater degradation o f the lig j iin in the younger c lo v e r than in
th e more mature c lo v e r fed to sheep*
MeJLnally (119) rep orted a l o s s o f lig n in during d ig e s tio n o f straw in
th e rumen and a lso w ith rumen co n ten ts in v i t r o *

Bondi and Meyer (27) re­

ported th a t th e d i g e s t i b i l i t y c o e f f i c i e n t s o f lig n in w ith sheep ranged be­
tween 35 and 64, depending upon the p la n t m a ter ia l fed*

They a lso reported

th a t f e c e s lig n in gave lower m ethoxyl v a lu e s than p la n t lig n in which th ey
b e lie v e d in d ic a te d an atta ck on th e lig n in m olecule during passage through
th e d ig e s t iv e tr a c t*

Louw (113) reported th a t sheep were able to d ig e s t

24.5 p ercen t o f the lig n in in grass one-m onth-old and o n ly 11*6 p ercen t
when th e *>am& grass

four months o ld .

D avis e t a l . (5 0 ) found the d i­

g e s t i b i l i t y o f l i gnin in pea v in e s and lim a bean v in e s as 16*0 and 1 0 .6
p e r c e n t, r e sp e c tiv e ly *
E l l i s , Matrone and Maynard (6 2 ) and Gray (83) have used an enzym atic
d ig e s tio n fo llo w ed by a d ilu t e a c id treatm ent before allow in g the m a ter ia l
to r e a c t w ith the stron g acid in the d eterm ination o f l ig n i n .

They have

shown w ith t h i s method o f d eterm ination th a t the lig n in o f c e r ta in fo ra g es
i s co m p letely in d ig e s tib le *

Crampton and Maynard (46) had p r e v io u sly r e ­

ported l ig n i n to be d ig e s t ib le to th e e x te n t o f more than 30 p ercen t in
feed b a r le y , wheat screen in g s and feed o a t s , but was alm ost com p letely
in d ig e s t ib le by the m o d ific a tio n o f Crampton and Ifh itin g (47) in which
th e l ig n in i s determ ined by d if fe r e n c e .

The p r in c ip a l source o f d is ­

crepancy may be th e varying proportions o f n o n -lig n in m a te r ia ls accounted
fo r by th e d if f e r e n t methods o f determ in ation .

The n e g a tiv e d ig e s tio n

c o e f f i c i e n t s reported o c c a s io n a lly are probably ex p la in ed on the b a s is o f
sm aller n itr o g e n c o n ten ts o f the l ig n i n is o la t e d from the feed s than are
ob tain ed from the l ig n i n is o la t e d from the f e c e s .

Arm itage, Ashworth and

F e rg u so n (4 ) have s u g g e s te d a p r e li m i n a r y tr e a tm e n t w ith t r y p s i n and d i l u t e
a c i d t o m in im iz e t h i s
L a n c a ste r

(11 0 )

erro r.
re p o rte d th e

c o rre la tio n

c o e f f i c i e n t s o f th e am ount o f

l i g n i n w i t h t h e c o n t e n t and d i g e s t i b i l i t y o f o t h e r p l a n t c o n s t i t u e n t s .
r e s u lts are

shown i n T a b l e 4 .
T ab le 4 .

C o r r e l a t i o n C o e f f i c i e n t s o f L ig n in U ith O th e r Feed C o n s t i t u e n t s
percen t

d ig e s tio n o f o rg a n ic m a tte r

-0 .S 7 8

Pe r c e n t

d i g e s t i o n o f cru de f i b e r

-0*954

p ercen t

d ig e s tio n of c e llu lo s e

-0 .9 1 S

P ercen t

d ig e s tio n o f p en to san s

-0 .9 0 6

C ru d e f i b e r c o n t e n t o f f e e d

+ 0 .9 5 5

C e llu lo se

+ C .7 7 0

c o n t e n t o f feed.

^From L a n c a s t e r ( 1 1 0 ) .
S w an so n a n d lie rm a n ( 1 7 6 ) f o u n d t h e

d ig e stib ility

of p r a c tic a lly a l l

o f t h e d e t e r m i n e d n u t r i e n t s o f K o r e a n l e s p e d e z a h a y d e c r e a s e d a s t h e ma­
tu rity

a d v an c ed and th e l i g n i n c o n t e n t i n c r e a s e d .

A c o m p ila tio n o f p u b lis h e d r e g re s s io n eq u a tio n s
c o n t e n t a n d th© d i g e s t i b i l i t y

o f t h e dry m a tte r

is

re la tin g

th e l i g n i n

g i v e n i n T a b l e 5.

The

39

T able 5,
R e g r e s s i o n E q u a t i o n s R e l a t i n g D i g e s t i b i l i t y o f DryM a tte r to t h e

L ig n in C o n te n t o f R a tio n

R e g re s s io n E q u a tio n

C o rrel
C oeff.

M a te ria l

Y = 93.9 -

-0 .9 3 9

A lfa lfa

P h illip s

and L o u g h l i n ( 1 5 1 ) .

-0 .9 5 4

T im o th y

P h illip s

and L o u g h l i n ( 1 5 1 ) .

S u lp h ite
C e l l u l o se

H v id ste n (9 5 ).

Y = 1 2 0 .3 Y = 8 4 .9

-

3 .0 4 X
5 . 9 6X
1 .1 5 X

—

Y = 9 5 . 9 - 4 .0 6 X

-0 .9 7

Y=96.4- - 4 .4 4 X

---------

Y=lOO - 4 . 7 IX

- 0 .9 5

Y=100 - 5 .2 4 X

-0 .9 3

Y=97 - 4 . 3 3 X

H o rd fe ld t e t a l .

———

Y=100 - 5 .3 2 X
Y=96 - 4 . 8 1 X

———

Y=100 - 4 . 9 2X

——

Y=94-

—

R eference

(1 3 2 ).

F o r b e s and G a r r i g u s

(7 0 ).

F o r b e s and G a r r i g u s
S te e rs ,
P a stu re
It
M
W eth ers,
P a stu re
tt
it
B ro m eg rass
P a stu re
w
«
O rc h .G ra s s
P a stu re
Ky.31 F e s c u e "
"
P a s t u re
ii
tt
A lfa lfa

(7 1 ).
it

it

w
,T
m

Pasture
-

2 .9 5 X

L a n c a ste r (1 1 0 ).

—

E f f e c t o f M eth o x y l C o n te n t o f P l a n t s on D i g e s t i b i l i t y
T here i s

some i n d i c a t i o n t h a t c h a n g e s i n t h e l i g n i n m o l e c u l e o r i n i t s

d i s t r i b u t i o n t h r o u g h t h e c e l l w a l l may h a v e m o re e f f e c t o n d i g e s t i b i l i t y o f
o th e r c o n s ti tu e n t s th a n th e

q u a n tity of lig n in p re s e n t.

M an g o ld ( 1 1 5 ) a n d

Woodman a n d S t e w a r t ( 1 9 0 , 1 9 1 ; h a v e shown t h a t t h e d e c r e a s e i n d i g e s t i b i l i t y
o f g r a s s e s w i t h i n c r e a s i n g m a t u r i t y m<ay b e a c c o m p a n i e d b y r a t h e r
c r e a s e s i n th© l i g n i n c o n t e n t .
a l l y i n c r e a s e s and t h e r e
th e lig n in .

sm all in ­

As p l a n t s m a t u r e , t h e l i g n i n c o n t e n t u s u ­

is also

(1 3 6 * 1 4 7 , 1 4 8 , 1 4 9 ; .

an i n c r e a s e i n t h e m e t h o x y l c o n t e n t o f

40

F ran cois e t a l . (7 5 ) found t h a t a p p r o x i m a t e l y 50 p e r c e n t o f t h e t o t a l
m e t h o x y l c o n t e n t , 50 p e r c e n t o f t h e m e t h o x y l c o n t e n t o f t h e l i g n i n ,

a n d 90

p e r c e n t o f t h e m e t h o x y l c o n t e n t o f t h e p e c t i n i n r a t i o n s f e d t o tw o c a l v e s
d is a p p e a r e d , a s i n d i c a t e d fro m a n a l y s i s o f th e u rin e
10- d

ay c o lle c tio n

p e r io d s on r a t i o n s

and fe c e s *

They u s e d

c o n ta in in g a l f a l f a hay a lo n e , a l f a l f a

p l u s d r i e d b e e t p u l p , a l f a l f a p l u s w h e a t, and a l f a l f a p l u s d r i e d b e e t p u lp
a n d w h e a t*

P h illip s

e t a l . (1 5 0 ) an d C sonka, P h i l l i p s and J o n e s ( 4 8 ) h ad

p r e v i o u s l y r e p o r t e d a 15 p e r c e n t l o s s o f m e t h o x y l i n t h e d i g e s t i v e

tra c t

o f a d o g a n d a 37 p e r c e n t l o s s b y a cow*
The m e t h o x y l c o n t e n t o f g r a s s a n d f e c e s h a s b e e n r e p o r t e d b y R e i d
(1 5 3 ) t o

show a h i g h n e g a t i v e c o r r e l a t i o n t o t h e t o t a l d i g e s t i b l e n u t r i ­

e n ts c o n te n t o f th e g rass*

The c o r r e l a t i o n c o e f f i c i e n t s r e l a t i n g t h e

m e th o x y l c o n t e n t o f g r a s s w ith th e a p p a r e n t d i g e s t i o n c o e f f i c i e n t s o f
s e v e r a l c o n s ti tu e n t s of th e

g r a s s a r o shown i n T a b le
T a b le

6

6.

.

C o r r e l a t i o n o f M e th o x y l C o n te n t o f G ra ss w i t h t h e A p p a r e n t
D ig e s tio n C o e f f ic ie n t s o f S e v e ra l G rass C o n s titu e n ts
C o n stitu e n t

o
C o rre la tio n C o e ffic ie n t^

C e llu lo se

-0*900

H e m ic e llu lo se s

-0 .8 9 6

C ru d e F i b e r

-0 .8 8 7

Pe c t i n s

-0 .8 6 5

S ta rc h

-0 .9 2 1

C rude P r o t e i n

-0 .9 3 3

T o tal d ig e s tib le n u tr ie n ts

-0 .9 6

^■From E e i d ( 1 5 3 ) *
2A11

c o e f f ic ie n ts h ig h ly s ig n if ic a n t.

41

R e id (1 5 3 ) a l s o p o i n t e d o u t t h a t th e m e th o x y l c o n t e n t o f g r a s s c u t a t
a la te
it

s t a g e h a d i n c r e a s e d 32*9 p e r c e n t i n m e t h o x y l c o n t e n t o v e r t h a t w h i c h

c o n t a i n e d w hen c u t a t a n e a r l y s t a g e *
P h illip s

a n d G o ss ( 1 4 8 ) h a v e shown t h a t t h e m e t h o x y l c o n t e n t o f p l a n t s

is n o t e n tire ly

a s s o c i a t e d w ith t h e l i g n i n m o le c u le and th e p r o p o r t i o n o f

t h e t o t a l am o u n t w h ic h i s

a s s o c i a t e d w i t h t h e l i g n in m o le c u le i n c r e a s e s

w i t h m o re m a t u r e p l a n t s *

E f f e c t o f S ta g e o f M a tu r ity on D i g e s t i b i l i t y
S c i e n t i f i c w o rk e rs and l i v e s t o c k

f e e d e r s h a v e u n d o u b te d ly b e e n aw are

o f th e d i f f e r e n c e i n n u t r i t i v e v a lu e o f roughages h a r v e s te d a t d i f f e r e n t
s t a g e s o f m a t u r i t y lo n g b e f o r e e x p e r i m e n t a l d a t a w ere c o l l e c t e d on t h i s
su b je c t*

The p r i m a r y p u r p o s e o f t h i s

s e c t i o n i s to r e v ie w th o s e e x p e r i ­

m e n t s w h ic h i n v e s t i g a t e d c h a n g e s i n t h e d i g e s t i b i l i t y o f t h e d r y m a t t e r o f
f o ra g e s o r o f th e v a rio u s c o n s ti tu e n t s o f th e d ry m a tte r and w i l l n o t a t ­
te m p t to r e v ie w a l l o f t h e s t u d i e s w h ic h have i n v e s t i g a t e d ch a n g e s i n
c h e m ic a l c o m p o sitio n w ith v a r io u s s ta g e s o f m a tu r ity o f p la n ts *
M ills

(1 2 4 ) and F o s te r

and M e r r i l l ( 7 3 ) a t t h e U t a h A g r i c u l t u r a l

E x p e r i m e n t S t a t i o n c u t a l f a l f a when t h e

f i r s t b l o s s o m s a p p e a r e d , when i n

f u l l b lo o m , a n d w h en h a l f o f t h e b l o s s o m s h a d f a l l e n *

They p r o d u c e d t h e

g r e a t e s t a m o u n ts o f b e e f p e r u n i t o f h a y f r o m t h e e a r l i e s t s t a g e s an d t h e
s m a l l e s t a m o u n ts f r o m t h e m o s t m a t u r e s t a g e *
t a i n e d t h e h i g h e s t am ount o f p r o t e i n *
cut a lfa lfa

The e a r l i e s t s t a g e a l s o c o n ­

S a lm o n , S w a n so n and Me Camp be 11 ( 1 6 0 )

a t t h o b u d , o n e - t e n t h b lo o m , f u l l b lo o m a n d s e e d s t a g e s .

The

a s h and p r o t e i n c o n t e n t d e c r e a s e d a s th e m a t u r i t y ad v an ced end th e c ru d e
fib e r

c o n te n t in c re a s e d .

S ix ty -to n in e ty -d a y feed in g t e s t s

co n d u cted f o r

t h e v a r io u s c u t t i n g s on t h r o e d i f f e r e n t y e a r s w i t h s t e e r s on th e a l f a l f a
hay w ith o u t any o th e r fe e d

showed t h a t 1628 p o u n d s o f bud s t a g e h a y p r o d u c e d

100

pounds of g ain in liv e -w e ig h t

b lo o m h a y ,
hay *

as com pered t o

2*163 p o u n d s o f f n l l - b l o o m h a y ,

D ig e s tio n t r i a l s

2 ,0 8 6 p o u n d s o f o n e - t e n t h

and 3 , 9 1 0 p o u n d s o f s e e d - s t a g e

show ed a n a v e r a g e d i g e s t i o n c o e f f i c i e n t o f 78 p e r ­

c e n t f o r t h e p r o t e i n i n h a y c u t a t t h e bud s t a g o ,
t h e o n e - t e n t h b lo o m a n d f u l l - b l o o m h a y s ,
h a y c u t a t th e seed sta g e *

73 p e r c e n t f o r t h a t i n

end 67 p e r c e n t f o r t h a t i n t h e

The c r u d e f i b e r i n t h e b u d s t a g e h a y s h a d a n

a v e r a g e d i g e s t i o n c o e f f i c i e n t o f 35 p e r c e n t ,

a s co m p a re d t o

an a v e r a g e o f

48 p e r c e n t f o r t h e o n e - t e n t h b lo o m , 43 p e r c e n t f o r t h e f u l l b lo o m , a n d 41
p e r c e n t f o r th e

so e d -sta g e hay.

Woodman, E v a n s an d N orm an ( 1 8 8 , 1 8 9 ) c o n ­

d u c te d d i g e s t i o n t r i a l s w i t h sheep on a l f a l f a c u t a t t h e p re b u d , bud, and
flo w e rin g s ta g e s .

A l f a l f a c u t a t a p r e b u d s t a g e w as s u p e r i o r t o

la te r

c u t t i n g s and com pared f a v o r a b l y w i t h young p a s t u r e g r a s s i n n u t r i t i v e
v alu e*

They a l s o p o i n t e d o u t t h a t t h e a l f a l f a p l a n t p r o d u c e d f i b e r a t

a n e a r l y s t a g e o f g r o w th a n d t h a t t h e d i g e s t i b i l i t y o f t h e f i b e r d i m i n ­
is h e d r a p id l y as a r e s u l t of l i g n if ic a tio n *
c o n t e n t w as 2 8 . 1 p e r c e n t f o r f i v e
2 1 .5

c u t t i n g s o f p re b u d h a y a s com pared t o

and 1 9 * 3 p e r c e n t f o r t h e b u d s t a g e and b lo o m s t a g e c u t t i n g s ,

tiv e ly .

respec­

T he c r u d e f i b e r c o n t e n t a v e r a g e d 1 9 . 3 p e r c e n t f o r t h © ' p r e b u d

s ta g e , in c re a s e d to
hay.

The a v e r a g e c r u d e p r o t e i n

2 6 .5 f o r t h e bud s t a g e ,

and 27 f o r t h e b lo o m s t a g e

The d i g e s t i o n c o e f f i c i e n t s w e r e c o n s i d e r a b l y h i g h e r f o r h a y c u t i n

t h e p re b u d s ta g e th e n f o r t h e h a y s c u t a t th o l a t e r

sta g e s.

The d i g e s t i o n

c o e f f i c i e n t s f o r c r u d e p r o t e i n a v e r a g e d 80 p e r c e n t f o r t h e p r c b u d s t a g e ,
78 p e r c e n t f o r t h e bud s t a g e , and 76 p e r c e n t f o r t h e b lo o m s t a g e h a y .
D ig e s tio n c o e f f i c i e n t s f o r crude f ib e r
th re e

s ta g e s, re s p e c tiv e ly .

o n e -fo u rth , o n e -h a lf,
d e c r e a s e d an d t h e

a v e r a g e d 6 4 , 48 a n d 43 f o r t h e

S o to la (17 0 ) c u t i r r i g a t e d

a n d t h r e e - f o u r t h b lo o in s t a g e s .

fib e r

co n te n t in c re a se d

a lf a lf a hay a t

The p r o t e i n c o n t e n t

as th e p l a n t s m a tu re d .

c u t a t t h e o n e - h a l f b lo o m s t a g e w as h i g h e s t i n d i g e s t i b l e

The h a y

crude p r o t e i n

43

and i n t o t a l d i g e s t i b l e n u t r i e n t s .

The d i g e s t i o n t r i a l s

o f h le w la n d e r e t a l .

( 1 2 9 ) w i t h cows o n s u n - c u r e d a l f a l f a t h a t w as c u t a t t h e o n e - h a l f b lo o m
s ta g e gave an a v e ra g e d i g e s t i o n c o e f f i c i e n t f o r c ru d e p r o t e i n o f 7 8 .3 f o r
t h e n o - b l o o m a n d 6 5 . 8 f o r t h e o n e - h a l f b lo o m h a y .

The d i g e s t i o n c o e f f i c i e n t s

o f t h e n i t r o g e n - f r e e e x t r a c t com pared c l o s e l y f o r b o th h a y s , b u t c r u d e f i b e r
a v e r a g e d 5 5 . 3 f o r t h e n o - b l o o m s t a g e an d 5 3 . 2 f o r t h e o n e - h a l f b lo o m h a y ,
The t o t a l d i g e s t i b l e

n u t r i e n t c o n te n t o f th e d r y m a tte r

av era g ed 6 3 .3 p e r ­

c e n t f o r t h e n o - b l o o m h a y and. 5 8 . 3 p e r c e n t f o r t h e o n e - h a l f b lo o m h a y .
D aw son , K o p la n d and G r a v e s ( 5 l )
cu t in th re e sta g e s,
10

r e p o r te d th e d i g e s t i b i l i t y o f a l f a l f a hay

a s f o l l o w s 5 ( 1 ) i n i t i a l b lo o m s t a g e , when n o t m o re t h a n

p e r c e n t o f t h e p l a n t s w e r e i n b lo o m ; ( 2 ) o n e - h a l f b lo o m s t a g e ; and ( 3 )

f u l l b lo o m s t a g e , w h e n 90 t o 1 0 0 p e r c e n t o f t h e p l a n t s w e r e i n b lo o m .

D i­

g e s t i o n t r i a l s o f f i f t e e n - d a y s c o l l e c t i o n s w ere c o n d u c te d w ith s h e e p .

The

a v e ra g e d i g e s t i o n c o e f f i c i e n t f o r th e

c r u d e p r o t e i n w as 7 7 . 7 f o r t h e i n i t i a l

b lo o m h a y a s c o m p a r e d t o 7 7 . 1 f o r t h e o n e - h a l f b lo o m a n d 7 5 . 4 f o r t h e f u l l
b lo o m h a y .

T he d i g e s t i o n c o e f f i c i e n t s f o r

th e c ru d e f i b e r a v e r a g e d 4 7 .7

f o r t h e i n i t i a l b lo o m , 4 1 . 4 f o r t h e o n e - h a l f b lo o m , and 3 8 . 3 f o r f u l l b lo o m
hay.

The t o t a l d i g e s t i b l e n u t r i e n t s o f t h e d r y m a t t e r w as 5 9 . 0 p e r c e n t f o r

t h e i n i t i a l b lo o m ,

5 6 . 7 f o r t h e o n e - h a l f b lo o m , and 5 3 . 9 f o r

th e f u l l b lo o m

hay,
S o t o l a ( 1 7 1 ) h a s shown t h a t t h e d i g e s t i b i l i t y

o f w h e a t and b a r l e y p l a n t s

d o e s n o t d e c r e a s e p r o g r e s s i v e l y w ith , a d v a n c i n g m a t u r i t y s i n c e t h e m i l k an d
dough s ta g e s o f th e g r a in fo rm a tio n y i e l d h ig h ly d i g e s t i b l e n u t r i e n t s t h a t
l a t e r decrease in d i g e s t i b i l i t y
th e p l a n t .

S o to la

(172) a lso

due to m a t u r a t i o n o f t h e v e g e t a t i v e p a r t o f

com pared t h e d i g e s t i o n c o e f f i c i e n t s f o r c r e s t e d

w heat g ra ss c lip p e d a t fo u r-in c h
apparent d i g e s t ib il ity
m a tte r,

f o r th e

a rd t e n - i n c h h e i g h t s .

The c o e f f i c i e n t s o f

f b u r - i n c h and t e n - i n c h c u t t i n g s w o re ; d ry

6 6 . 7 and 6 G .7 ; c r u d e p r o t e i n ,

7 4 . 3 an d 5 9 . 7 ; c r u d e f i b e r ,

S 3 .5 an d

44

6 7 . 85 and n i t r o g e n - f r e e e x t r a c t ,

7 4 . 5 an d 7 4 . 8 , r e s p e c t i v e l y .

T h i s com­

p a riso n

i l l u s t r a t e s t h e v a l u e o f a c o m p a riso n o f

th e d i g e s t i b i l i t y o f th e

v a rio u s

c o n s t i t u e n t s i n c o n t r a s t t o a c o m p a riso n

o±* o n l y t h e d r y m a t t e r

d i g e s t i b i l i t i e s i n a p a s tu r e e v a lu a tio n stu d y .

S o t o l a (1 7 3 )

stu d ie d

c h a n g e s i n c h e m ic a l c o m p o s itio n and a p p a r e n t d i g e s t i b i l i t y o f n u t r i e n t s
i n s m o o th brom e g r a s s c u t a t r e g u l a r i n t e r v a l s d u r i n g t h e g r o w in g s e a s o n .
The c r u d e p r o t e i n d e c r e a s e d f r o m 1 3 . 6 t o 4 . 0 p e r c e n t 'w h ile t h e c r u d e f i b e r
i n c r e a s e d fro m 1 9 .8 t o 3 5 .9 p e r c e n t d u r in g g ro w th o f t h e p l a n t s fro m 4 .5
to

36 i n c h e s i n h e i g h t .

The d r y m a t t e r w as 81 p e r c e n t d i g e s t i b l e

f o u r - and t e n - i n c h s t a g e s and o n l y 5 5 .8 p e r c e n t d i g e s t i b l e a t t h e
sta g e .

D i g e s t i b i l i t y o f th e crude p r o t e i n , crude

e x tra c t

fo llo w e d s i m i l a r tr e n d s .

fib e r

a t th e
3 6 -in c h

an d n i t r o g e n - f r e e

The d i g e s t i b i l i t y o f a m i x t u r e o f v e l d g r a s s e s c u t a f t e r p e r i o d s o f
1,

2, 3 and 4 m o n th s g ro w th m s

s t u d i e d by Louw ( 1 1 3 ) .

W i th i n c r e a s i n g

m a t u r i t y o f t h e g r a s s t h e p e r c e n t a g e o f n a t u r a l c e l l u l o s e and t h e r a t i o
x y la n to t r u e c e l l u l o s e

in c re a se d

slig h tly .

h e m ic e l lu lo s e c o n t e n t s w ere r e l a t i v e l y s m a ll.

of

The i n c r e a s e i n . t h e l i g n i n a n d
The d i g e s t i b i l i t y

o f c e llu ­

l o s e , p e n t o s a n s and h e m i c e l l u l o s e a l l d e c r e a s e d w i t h a d v a n c in g m a t u r i t y .
D i j k s t r a an d B ro u w e r ( 5 4 ) r e p o r t e d on c h a n g e s i n c h e m i c a l c o m p o s i t i o n and
f e e d in g v alu e o f

g r a s s mowed a t d i f f e r e n t s t a g e s o f m a t u r i t y .

7sri t h

in ­

c r e a s i n g ag e o f t h e g r a s s t h e p e r c e n t a g e o f p r o t e i n d e c r e a s e d an d t h e p e r ­
cen tag e of c e llu lo s e in c re a s e d .
w ith in c re a s in g m a tu rity .
cru d e c e llu lo s e
tria ls

D i g e s t i b i l i t y and f e e d i n g v a l u e d e c r e a s e d

They a l s o r e p o r te d th e d i g e s t i b i l i t y

a s n o t a p p r e c i a b l y d i f f e r e n t from t h e

w ith sheep.

and l a t e

sta rc h in d ig e stio n

B u r k i t t (27) co n d u cted d i g e s t i b i l i t y t r i a l s w ith sheep

on b e a r d le s s w h eat g ra s s c u t a t an e a r l y
in c h e s)

o f th e

stage- o f g r o w t h .

( 3 t o 5 i n c h e s ) , m edium ( 7 t o

10

The c o e f f i c i e n t o f a p p a r e n t d i g e s t i b i l ­

i t y o f a l l t h e v a r io u s n u t r i e n t s d ro p p e d a s th e g r a s s m a tu re d .

S w a n so n

45

a n d H erm an ( 1 7 6 ) f o u n d t h e d i g e s t i b i l i t y o f p r a c t i c a l l y a l l t h e n u t r i e n t s
o f K o r e a n l e s p e d e z a h a y d e c r e a s e d w i t h a d v a n c i n g m a t u r i t y an d i n c r e a s i n g
l i g n i n c o n te n t*

The d i g e s t i b i l i t y t r i a l s "were c o n d u c t e d w i t h d a i r y h e i f e r s *

U n d erw o o d a n d M o ir ( 1 8 0 ) c o n d u c t e d d i g e s t i o n t r i a l s w i t h s h e e p o n w h e a t
and o a t h ay c u t a t v a r i o u s p e r i o d s o f g ro w th r a n g in g fro m b e f o r e f l o w e r i n g
t o w h e n t h e g r a i n w as p r a c t i c a l l y m a t u r e *

The f i r s t c u t t i n g o f w h e a t h a y

had th e h ig h e s t d ig e s tio n c o e f f i c i e n t f o r a l l c o n s ti tu e n t s ,
e th e r e x tra c t*

ex c e p t th e

The c r u d e p r o t e i n a n d f i b e r h a d d e c i d e d l y l o w e r d i g e s t i o n

c o e f f ic ie n ts in th e l a t e r

c u t t i n g s o f b o t h th e w h e a t and o a t h a y ,

A d e c lin e

i n t h e d i g e s t i b i l i t y o f p a s t u r e h e r b a g e d r y m a t t e r f r o m a b o u t 75 p e r c e n t
f o r e a r ly sp rin g g rass to

60 p e r c e n t a b o u t s i x w e e k s l a t e r was r e p o r t e d

b y C r a m p to n an d J a c k s o n ( 4 4 ) .

D r a p a l a , Raymond and

C ram pton ( 5 5 ) made

h i s t o l o g i c a l e x a m in a tio n s o f th e p l a n t r e s i d u e s i s o l a t e d from t h e f e c e s
o f s h e e p o n c l o v e r c u t a t v a r i o u s s t a g e s o f m a t u r i t y and f o u n d t h e i n c r e a s e
i n t h e number o f u n d i g e s t e d b i t s o f p l a n t t i s s u e s i n t h e f e c e s and t h e i r
i n c r e a s e i n s i z e was c o r r e l a t e d w i t h t h e i n c r e a s e i n m a t u r i t y o f t h e f o r ­
a g e e a t e n and i t s

in c re a sin g lig n ific a tio n *

D ecreases in d i g e s t i b i l i t y

h a v e b e e n show n t o b© a s s o c i a t e d w i t h a d v a n c i n g m a t u r i t y i n f l a t p e a f o r by D a n ie l e t a l .

( 4 9 ) , t i m o t h y h a y b y C o lo v o s e t a l *

g r a s s by D u n lo p a n d Coup ( 5 8 ) .

( 3 8 ) , a n d p am pas

R eid (1 5 5 ) h a s a l s o r e c e n t l y r e p o r t e d

t h a t t h e d i g e s t i o n c o e f f i c i e n t s o f t h e d r y m a t t e r o f e a r l y , m edium a n d
la te

c u t g r a s s w as 7 2 * 2 ,

66*6

and 5 6 .0 , r e s p e c t i v e l y .

E f f e c t o f P l a n t A sh on D i g e s t i b i l i t y .
B urroughs e t a l .

( 3 o ) f i r s t p r e s e n t e d e v i d e n c e w h ic h i n d i c a t e d t h e

p r e s e n c e o f n u t r i e n t s i n a l f a l f a hey t h a t h ad a f a v o r a b l e i n f l u e n c e on
t h e d i g e s t i b i l i t y o f a p o o r q u a l i t y r o u g h a g e w hen f e d t o c a t t l e .
p re v io u s e x p e rie n c e

T h e ir

(32) in f in d i n g t h a t c o rn s ta r c h e x e r te d l i t t l e

o r no

46

e f f e c t u p o n t h e d i g e s t i b i l i t y o f t h e d r y m a t b e r o f g ood q u a l i t y a l f a l f a
h a y ; h u t w hen a d d e d t o a p o o r q u a l i t y r o u g h a g e ( c o r n c o b s ) , t h e c o r n s t a r c h
c a u s e d a m ark ed d e c r e a s e m

t h e d i g e s t i b i l i t y o f t h e rou g h ag e d r y m a tte r *

These r e s u l t s in d i c a te d t h a t a l f a l f a hay c o n ta in e d c e r t a i n n o n - p r o te in
m a t e r i a l e s s e n t i a l f o r t h e g r o w th o f ru m e n m i c r o o r g a n i s m s n e c e s s a r y f o r
ro u g h ag e d i g e s t i o n s in c e a p p ro x im a te ly th e
fe d w ith each o f th e ro u g h ag es stu d ie d *

same a m o u n ts o f p r o t e i n w e r e

They f e l t t h a t i f

a ro u g h ag e i s

f e d w i t h s t a r c h t h e d i g e s t i b i l i t y w i l l n o t be l o w e r e d i f t h e r e
c i e n t ©mount o f t h e unknown n u t r i e n t s t o
o rg a n ism s s u b s i s t i n g on b o th th e

is a s u f f i­

su p p ly th e re q u ir e m e n ts o f m ic r o ­

s t a r c h and t h e

ro u g h a g e , how ever, i f

s u f f i c i e n t q u a n t i t i e s o f th e s e n u t r i e n t s are n o t p re s e n t in th e ro ughage,
th e

s ta rc h w ill decrease th e d i g e s t i b i l i t y

o rg a n ism s a t t a c k i n g

o f th e roughage s in c e th e m ic ro ­

s t a r c h w i l l d e p l e te th e roughage o f n u t r i e n t s need ed

f o r t h e a p p a r e n t l y slo w e r a c t i n g m ic ro o rg a n ism s c o n c e rn e d i n roughage d i ­
g e s t i o n j» B u r r o u g h s e t a l .

(35) re p o rte d a s e r ie s o f th r e e d ig e s t io n t r i a l s

u s in g g rad e H e re fo rd s t e e r s as fo llo w s j (1 ) d i g e s t i o n o f co rn co b s i n
r a t i o n s c o n t a i n i n g ■ v a r ia b le a m o u n ts o f h a y ,

(2) d i g e s t i o n o f co rn co b s i n

r a t i o n s w i t h and w it h o u t a d d i t i o n s o f a w a te r e x t r a c t o f a l f a l f a h a y , and
(3 ) th e in flu e n c e o f a l f a l f a

a sh upon corncob d i g e s t i o n .

In th e f i r s t

s e r i e s e ac h in c re m e n t o f a l f a l f a h ay ( 0 .5 t o 5 .0 pound) i n t h e r e s p e c t i v e
ra tio n s re su lte d

in in c re a s e d d ig e s tio n o f co rn co b s.

S im i la r e f f e c t s w ere

s e c u re d w ith th e a d d i tio n o f a w a te r e x t r a c t of a l f a l f a to th e
t h o u g h t h e r e s p o n s e w as q u i t e

s lo w and t h e

ra tio n a l­

in c re a s e d d i g e s t i b i l i t y con­

t i n u e d f o r a s h o r t t i m e a f t e r rem ove 1 o f t h e w a t e r e x t r a c t o f a l f a l f a .
The a d d i t i o n o f a l f a l f a a s h a p p r o x i m a t e l y e q u i v a l e n t t o t h a t f o u n d I n
f o u r p o u n d s o f a l f a l f a m e a l was f e d t o
tio n t r i a ls .

each of fo u r s te e rs

i n tw o d i g e s ­

The a d d i t i o n o f t h e a l f a l f a a s h I n c r e a s e d t h e d i g e s t i b i l i t y

47

o f th e dry m atter from 3 1 .6 percent in th e c o n tr o l period to 4 3 .5 p ercen t
i n th e supplemented period*
S w ift e t a l * (1 77) extended th e work reported by Burroughs (33) to
a comparison o f th e m etab olizab le energy and methane production o f sheep
fed a b a sa l r a tio n con tain in g 40 percent ground com cobs and the b a sa l
r a tio n p lu s a l f a l f a ash*

They reasoned th a t an in crea se in the apparent

d i g e s t i b i l i t y o f dry m atter and crude fib e r would be o f no valu e to th e
animal i f th e re was an in crea se in methane production corresponding to
the d ecrease in f e c a l output*

The d i g e s t i b i l i t y of a l l o f the r a tio n

c o n s titu e n ts was in crea sed by a l f a l f a ash supplem entation, but th e in crea se
in the d i g e s t i b i l i t y o f crude fib e r was the on ly one found to be h ig h ly
s ig n ific a n t*

The in c re a se in th e crude fib e r d i g e s t i b i l i t y was accom­

panied by a sm all in c r e a se in methane production which was small enough
th a t th e n e t e f f e c t o f a l f a l f a ash supplem entation was to in crea se the
amount o f fee d energy a v a ila b le to the anim al.
A sso c ia tiv e E ffe c t o f Feeds and D i g e s t i b i li t y
A s so c ia tiv e d i g e s t i b i l i t y i s th e term ap p lied to a change in the
d i g e s t i b i l i t y o f a fee d when incorporated in a r a tio n w ith one or more
o th er fe e d s as compared to i t s d i g e s t i b i l i t y when fed alone*

Ewing and

YSells (6 5 ) were app arently th e f i r s t to use the term , " a sso c ia tiv e d ig e s t ­
i b i l i t y ”, when they stu d ied mixed r a tio n s composed o f corn s i l a g e , c o tto n ­
seed m eal, and sta r c h .

The c o e f f i c i e n t s o f d i g e s t i b i l i t y fo r the co tto n ­

seed meal c a lc u la te d from th e mixed r a tio n with s ila g e were higher than
the v a lu e s fo r co tto n se ed meal fe d a lo n e , but the d iffe r e n c e s were rep ort­
ed to be n ot s ig n if ic a n t .

They la t e r (64) in v e stig a te d r a tio n s composed

o f c o m s ila g e , a l f a l f a , and v e lv e t bean meal in variou s combinations and
p r o p o r tio n s.

In the s ila g e and a l f a l f a r a tio n , s ila g e and v e lv e t bean

m e a l r a t i o n , v e l v e t b e a n m e a l and a l f a l f a r a t i o n ,
and v e l v e t b e a n m e al r a t i o n ,

and t h e

sila g e ,

a lfa lfa

th e c o e f f i c i e n t s o f d i g e s t i b i l i t y o f th e d ry

m a tte r , n itr o g e n , cru d e f i b e r ,

and n i t r o g e n - f r e e e x t r a c t o f t h e m ix e d

r a t i o n s w ere l e s s t h a n th e v a l u e s c a l c u l a t e d fro m th e c o e f f i c i e n t s o f th e
i n d i v i d u a l c o m p o n e n ts #

The d i f f e r e n c e s w e r e o n l y tw o t o f o u r a b s o l u t e p e r ­

cen t#
W a ts o n e t a l .

(1 8 4 ) s t u d i e d t h e a s s o c i a t i v e d i g e s t i b i l i t y o f d r y and

s u c c u l e n t r o u g h a g e s u c h a s m ix e d h a y , o a t s t r a w , o a t h u l l s , c o r n s i l a g e ,
a n d m a n g e l s when f e d t o

ste e rs*

The c o e f f i c i e n t s o f d i g e s t i b i l i t y we r e

d e te r m in e d when t h e s e f e e d s w ere f e d a s t h e
tio n s o f v a rio u s p a ir s o f th e se

s o l e r a t i o n an d w hen c o m b in a ­

f e e d s made up t h e r a t i o n .

The d i g e s t i b i l i t y

o f o n e o f t h e I n d i v i d u a l c o m p o n e n ts i n e a c h m ix e d r a t i o n was t h e n c o m p a re d
w ith i t s

d i g e s t i b i l i t y w hen f e d a l o n e .

hay, o a t

stra w ,

110

a sso c ia tiv e

on t o t a l

d ig e s tib ility o r to ta l d ig e stib le n u trie n ts .

They a l s o

t h a t th e

d ig e s tib ility of oat h u lls,

co rn s ila g e

e i th e r h ay, corn s ila g e ,

They c o n c lu d e d

and m a n g e ls t h e r e was

t h a t among m ix e d
effect
co n clu d ed

c a l c u l a t e d f r o m a m ix e d r a t i o n w i t h

o r m a n g e l s , was l o w e r t h a n t h e d i g e s t i b i l i t y o b ­

s e r v e d w h en o a t h u l l s c o n s t i t u t e d t h e s o l e r a t i o n ,

h f a ts o n e t a l « ( 1 8 5 )

d e te rm in e d th e d i g e s t i o n c o e f f i c i e n t s o f b a r le y , o a t s , o i l ca k e , ba r l e y
p l u s o a t s , and b a r l e y p l u s o a t s a n d o i l c a k e i n a b a s a l r a t i o n o f h a y by
u sin g s te e r s .

T h ey c o n c l u d e d t h a t t h e r e w as no a s s o c i a t i v e e f f e c t b e t w e e n

b a r l e y and o a t s and o n ly s l i g h t l y h i g h e r d i g e s t i b i l i t i e s o f th e d r y m a t t e r
o f t h e b a r l e y p l u s o a t s and o i l c a k e r a t i o n w e re f o u n d e x p e r i m e n t a l l y t h s n
w ere c a l c u l a t e d .

U s i n g r a t i o n s o f b a r l e y , o a t s and o i l c a k e a l o n e and

a l s o w hen t h e y w e r e f e d i n a m ix e d r a t i o n w i t h h a y , W a ts o n e t a l ,
r e p o r t e d o n t h e a s s o c i a t i v e d i g e s t i b i l i t y o f h a y and t h o s e
o i l c a k e t h e r e w e r e no s t a t i s t i c a l l y

g ra in s#

(182)
;ith

s i g n i f i c a n t d i f f e r e n c e s b etw ee n th e

v a l u e s o b t a i n e d b y c a l c u l a t i o n f r o m t h e m ix e d r a t i o n an d t h o s e o b t a i n e d

w hen t h e o i l c a k e c o n s t i t u t e d t h e e n t i r e r a t i o n *
tistic a lly

T h e r e w e r e a l s o no s t a ­

s i g n i f i c a n t d if f e r e n c e s in th e case o f b a rle y , e x c e p t fo r th e

e th e r e x tra c t*

The d i g e s t i b i l i t y o f t h e e t h e r e x t r a c t , c a l c u l a t e d f r o m

t h e m ix e d r a t i o n w i t h h a y , w as h i g h e r t h a n t h a t d e t e r m i n e d b y f e e d i n g t h e
b a r l e y alo n e*

W i th o a t s , e x c e p t f o r n i t r o g e n an d e t h e r e x t r a . c t , t h e v a l u e s

c a l c u l a t e d f r o m t h e m ix e d r a t i o n w i t h h a y w e re s i g n i f i c a n t l y l e s s t h a n t h e
v a l u e s o b t a i n e d w hen t h e o a t s w e re f e d a l o n e .

For a l l th re e fe e d s , w ith

t h e e x c e p t i o n - o f e t h e r e x t r a c t , t h e v a l u e s c a l c u l a t e d f r o m m ix e d r a t i o n s
w i t h h a y t e n d e d t o be l o w e r t h a n t h e v a l u e s o b t a i n e d b y f e e d i n g t h e

g ra in s

alo n e*

I t w as o n l y i n t h e c a s e o f o a t s t h a t su ch d i f f e r e n c e s w ere s i g n i f ­

ic a n t*

't f a t s o n ert a l » ( 1 8 3 ) a l s o d e t e r m i n e d t h e c o e f f i c i e n t s o f d i g e s t i b i l ­

ity

fo r w heat b ra n ,

g lu te n fe e d ,

o f eq u al p a r ts o f th e se

g ra in s.

s o y b e a n o i l m e a l , end a m i x t u r e c o n s i s t i n g
From t h e v a l u e s o f t h e i n d i v i d u a l g r a i n s

a c a l c u l a t i o n w as made o f t h e c o e f f i c i e n t s o f d i g e s t i b i l i t y o f t h e
m i x t u r e w h i c h w as p r a c t i c a l l y
d ig e stib ility tr ia ls .

I d e n t i c a l w i t h t h e v a l u e s d e te rm in e d by

They c o n c l u d e d t h a t t h e r e w as no a s s o c i a t i v e

g e s t i b i l i t y b etw een th e s e t h r e e
th e r e la tiv e

g ra in

g ra in s.

y ;a ts o n e t a l .

d i­

(1 8 6 ) r e p o r t e d on

a s s o c i a t i v e e f f e c t s o f t i m o t h y said a l f a l f a , h a y s w i t h b a r l e y

w hen u s i n g s t e e r s an d s h e e p and r a t i o n s
h a y an d m ix e d r a t i o n s
d ig e stib ility

of b a r l e y , tim o th y h ay , a l f a l f a ,

o f b a r l e y p l u s t i m o t h y and. b a r l e y p l u s a l f a l f a .

The

o f b a r l e y w h e n I t was f e d a l o n o w as co m p a re d w i t h t h e d i ­

g e s t i b i l i t y w hen c a l c u l a t e d f r o m t h e b a r l e y p l u s t i m o t h y r a t i o n a n d t h e
b a rle y p lu s a l f a l f a

ra tio n .

The d i g e s t i b i l i t y

o f b a r l e y w as t h e

w hen f e d w i t h t i m o t h y , w hen f e d w i t h a l f a l f a o r w hen f e d a l o n e t o

same
sheep

and s t e e r s .
S w ift e t a l .
d ig e stib ility

(178)

s tu d ie d th e e f f e c t of v a rio u s

o f a m ix e d r a t i o n

su p p le m e n ts on th e

f o r s h e e p , h o w e v e r , o a t s t r a w w as t h e

50

on ly n a tu ra l fee d supplement used*

The a d d itio n o f crude fib e r to the ra­

t io n in the fonn o f ©at straw reduced th e t o t a l amount o f p r o te in and eth er
e x tr a c t d igested *
Graves e t a l * (8 2 ) did not conduct d ig e s t io n t r i a l s in con n ection w ith
t h e ir experim en ts, b u t reported what appeared to be very l i t t l e d iffe r e n c e
in e f f i c ie n c y fo r m ilk production o f the t o t a l d ig e s t ib le n u tr ie n ts derived
from th e a l f a l f a and th a t d erived from th e grain , hay, and s ila g e ration*
F if t e e n H o lste in cows were kep t on a l f a l f a hay alone fo r two or th ree la c ­
t a t io n s and although the cows were unable to consume as much t o t a l d ig e s t ­
i b le n u tr ie n ts as in a hay and grain r a tio n , th ey were able to . u t i l i z e th e
n u tr ie n ts consumed w ith about th e same e ffic ie n c y *
E f f e c t o f A n tib io tic s on D i g e s t i b i l i t y
Many recen t rep orts have shown increased gains and a c ce le ra te d growth
o f se v e r a l sp e c ie s o f anim als r e c e iv in g v a riou s a n t ib io t ic supplements*
Some o f th e se experim ents tend to in d ic a te th a t a more e f f i c i e n t u t i l i z a ­
t io n o f n u tr ie n ts by the animal are r esp o n sib le fo r the in creased growth
or w eight g a in s, but sin c e d i g e s t i b i l i t y comparisons w ith and w ith ou t
th e se supplements have n ot been made th ese experim ents w i l l not be re­
viewed*

S everal experim ents w ith d if f e r e n t sp e c ie s o f animals have shown

th a t c e r ta in a n t i b io t i c s have a pronounced e f f e c t on the microorganisms
in th e i n t e s t i n a l t r a c t .

Since th e ruminant is p rim a rily dependent upon

an a c tiv e m icro b ia l f lo r a fo r e f f i c i e n t d ig e s tio n o f c e r ta in feed con­
s t i t u e n t s , i t seems reasonable th a t a n t ib io t ic s might a f f e c t the d ig e s t ­
i b i l i t y o f th e se n u tr ie n ts depending upon the groups o f organisms th a t
were most g r e a tly a ffe c te d by th e a n t ib io t ic m a teria l u sed .
B e ll, H fhitehair and Gallup (2 0 ,2 1 ) stu d ied th e d i g e s t i b i l i t y o f a
b a sa l r a tio n o f p r a ir ie hay, c o m , soybean o i l m eal, bonemeal and s a l t

51

w ith "three ste e r s*

The same b asal r a tio n p lu s 0*2 gram ©f c r y s t a llin e

aureomycin hydrochloride was fed to th r ee a d d itio n a l s t e e r s , one r e c e iv in g
o n ly aureomycin and tw® 45 grams urea plus aureomycin*

The s t e e r s were

kept in m etabolism s t a l l s and fed a con stan t amount of r a tio n during a
ten -d a y prelim in ary and a fif te e n - d a y c o lle c t io n period*

The th ir d day

a fte r aureomycin fee d in g was sta r te d two s te e r s developed m ild anorexia
and diarrhea*

About th e f i f t h day a l l th ree s t e e r s became s l i g h t l y con­

s tip a te d w ith symptoms o f b lo a t and th e ir f e c e s became dry and fibrous*
The e f f e c t o f aureomycin on the d i g e s t i b i l i t y o f various feed c o n s titu e n ts
by s t e e r s i s i ll u s t r a t e d by m a teria l in Table 7 taken from th e data o f
B e ll e t a l . ( 2 1 ) .

52

T a b le 7 .

E f f e c t o f Aureomycin on D ig e stio n C o e ffic ie n ts -with Steers^"
P ercent Apparent D i g e s t i b i li t y
S te er
No,
z

—

5-Day
P eriod

--------

Dry
Matter

Crude
P ro te in

--------

----------

and
5

Ether
E x t.

-------

Crude
F iber

-------

N-Free
E xt.

--------

(B asal R ation)
1

69.07

51.93

63.31

66.35

74.91

2

6 6 . 58

52.68

58.38

62.77

74.93

3

70.69

55.42

65.94

67.01

76.20

4

69.57

55.15

6 6.93

65.45

75.40

5

72.67

60.83

71.52

70.60

77.96

Av.

70.04

53.20

65.26

66.44

75.88

(B asal R ation + Aureomycin)

3—
1

76.36

65.64

74.63

66.29

81.86

2

63.71

56.27

62.76

49.71

70.48

3

58.00

47.60

66.51

55.88

67.25

4

54.06

45.31

60.50

30.72

65. 49

1

(B asal Ration + Urea * Aureomycin)

and
6

1

74.58

72.10

71.58

69.98

79.65

2

66.23

67.46

62.77

52.70

73.52

3

63.84

65.05

65.44

51.37

70.20

4

59.53

68.42

67.57

39.78

66.79

5

59.58

67.86

65.13

42.86

66.89

^From B e ll e t a l . ( 2 1 ) .
I t appears th a t the m ost pronounced e f f e c t o f aureongrcSn was on th e
d i g e s t i b i l i t y o f crude f ib e r which might su ggest th a t i t had a d etrim en ta l

53

®ff®ot

"th.® c e l lu l o s e d ig e s t in g microorganisms of* the i n t e s t i n a l tr a c t*

The d i g e s t i b i l i t y o f the dry matter and crude fib e r o f the r a tio n s was
markedly reduced in th e l a t t e r p a r t o f th e experiment*
SUMMARY OF THE REVIEW OF LITERATURE
D ig e s tio n t r i a l s in v o lv in g the t o t a l c o lle c t io n o f fe c e s during a
te n day period o f constan t feed intake have become a standard method fo r
determ ining th e d i g e s t i b i l i t y o f variou s feeds*
S ev eral in e r t m a te r ia ls have been proposed and stu d ied as a means o f
conducting d ig e s t io n t r i a l s by the s o -c a lle d in e r t m a teria ls " ratio te c h ­
n iq u e”.

A s a t is f a c t o r y in e r t m a terial should be f u l l y recoverable in th e

f e c e s and should have a n a ly t ic a l methods a v a ila b le th a t are e a s i l y con­
ducted and a ccu ra te.

In some in sta n c e s i t would be h ig h ly d e sir a b le to

have th e in e r t m a teria l a n a tu r a lly occurring c o n stitu e n t o f -the p la n t
being studied*
Chromium, ir o n , s i l i c a , l ig n i n , in d ig e s tib le n itr o g e n , c e r ta in p la n t
pigm ents and variou s s y n th e tic dyes have been proposed and stu d ied as
in e r t m a te r ia ls fo r use in th e r a tio technique fo r d i g e s t i b i l i t y s t u d ie s .
C o n tro v ersia l r e s u lt s have been reported w ith each o f th e se m a te r ia ls
th a t have been stu d ied by independent workers.
s a t is f a c t o r y r e s u lt s fo r se v era l in v e s t ig a t o r s .

Chromic oxid e has given
33ie method o f preparing

ft-na feed in g th e chromium may be an important fa c to r in i t s su c c e s sfu l
u se as an in e r t m a ter ia l w ith rum inants.

Wide ranges in the r e c o v e r ie s

o f l ig n in have been rep orted fo r various feed s Then fed to d if f e r e n t
anim als and when the l ig n i n a n a ly ses were made by d if f e r e n t methods.
The s u c c e s s fu l use o f l ig n i n as an in e r t m aterial depends upon a pre­
v io u s knowledge o f i t s recovery from th e feed in q u estion and w ith the
animal s p e c ie s in v o lv e d .

D ig e stio n c o e f f i c i e n t s c a lc u la te d from iron

54

r a t io s have bean h ig h ly v a r ia b le and in some c a se s iro n r e c o v e r ie s have
been very low*

U n sa tisfa c to r y r e s u lt s w ith the s i l i c a r a tio technique

have been reported when u sin g the n a tu r a lly contained feed s i l i c a and a ls o
when u sin g added amounts o f s ilic a *

A n a tu r a lly occurring p lan t pigment

or groups o f pigm ents have been reported which are f u l l y recoverab le in
th e f e c e s and have a ls o given s a t is f a c t o r y r e s u lt s when used as an in e r t
m a te r ia l in d i g e s t i b i l i t y t r i a l s w ith se v e r a l forages*

Only lim ite d com­

p a riso n s have been rep orted w ith th e p la n t pigment r a tio technique o f
studying d i g e s t i b i l i t y *

Further s tu d ie s o f sy n th e tic dyes are n ecessa ry

to ev a lu a te t h e ir u s e fu ln e s s in d i g e s t i b i l i t y stu d ies*

Wo stu d ie s have

been rep orted in which more than two in e r t m a te r ia ls have been stu d ied
in the same d ig e s tio n t r i a l u sin g th e same feed and the same animals*
L ig n in , crude f ib e r and c e llu lo s e a l l show high n eg a tiv e c o r r e la tio n s
w ith the d i g e s t i b i l i t y o f th e dry m atter o f feeds*

A n a ly sis o f fe e d s fo r

t h e ir co n ten t o f crude f ib e r has been c r i t ic i z e d because ih e crude f ib e r
i s n o t o f uniform com position -when is o la t e d from d iff e r e n t fe e d s and th e
d is tr ib u t io n o f th e variou s c o n s titu e n ts between th e crude fib e r and
n itr o g e n -fr e e e x tr a c t f r a c t io n s v a r ie s w idely w ith d if f e r e n t feeds*
PLAN OF EXPERIMENT AND METHODS USED
This study was planned to make a comparison o f the d ig e s t io n co­
e f f i c i e n t s determined w ith m ilk in g d a iry cows fed orchard grass hay c u t
a t fou r sta g e s o f m atu rity ty the fo llo w in g d ig e s tio n t r i a l tech n iq u es:
(1 )

T otal f e c a l c o ll e c t i o n technique*

(2 )

Chromium r a tio technique ( t o t a l c o lle c t io n )*

(3 )

P la n t pigment r a tio technique ( t o t a l c o lle c tio n ) *

(4 )

L ignin r a t io technique ( t o t a l c o lle c tio n )*

(5 )

Chromium r a tio technique (Grab samples)*

( 6)

P la n t pigment r a tio technique (Grab samples)*

55

The orchard grass hay used in t h i s study urns c u t from a second growth
th a t had been p r e v io u sly sprayed w ith 2,4-D fo r th e c o n tro l o f weeds end
c lo v e r .

Ammonium sulphate was ap p lied a t the r a te o f 100 and 150 pounds

per acre approxim ately one month and one week r e s p e c tiv e ly , b efore the
f i r s t experim ental c u ttin g was made*

The d if f e r e n t sta g e s o f m atu rity

were h arvested a t approxim ately two week in t e r v a ls as fo llo w s:
Stage 1

6 to 7 in ch es high* (P astu re S tage)

Cut May 19, 1949.

Stage 2

8 to 10 in ch es higjh*

(Late p astu re)

Cut May 51, 1949.

Stage 3

10 to 12 in c h e s high*

(E arly hay)

Cut June 14, 1949.

Stage 4

12 to 14 in ch es high*

(Mature Hay)

Cut June 27, 1949.

The f i r s t c u ttin g was c u t in th e f i e l d w ith a forage f i e l d chopper
and th e chopped m a te r ia l blown d ir e o t ly in to wagons and hauled to th e
bam fo r a r t i f i c i a l drying.

The l a s t th r e e c u ttin g s were l e f t i n th e

f i e l d fo r approxim ately one day and then windrowed w ith a sid e d e liv e r y
rake and chopped from the windrow w ith a forage f i e Id-chopper*
were d ried on a s la t t e d f lo o r bam d r ie r w ith supplemental h e a t.

A ll l o t s
A fter

d r y in g , each l o t o f hay was baled and sto red u n t il fe d .
D ig e stio n t r i a l s were conducted on each l o t o f hay u sin g th ree m ilk­
in g cows in d ig e s t io n s t a l l s th a t perm itted m echanical sep aration o f th e
f e c e s and urine*

Ten day prelim in ary period s and te n day experim ental

p erio d s were used fo r each l o t o f orchard grass stu d ie d .

The anim als

were kep t in th e d ig e s tio n s t a l l s during the e n tir e p relim in ary and
experim ental p erio d s ex cep t fo r a d a ily period o f w alking fo r e x e r c is e .
The fe e d in g schedule fo r th e variou s sta g e s o f orchard grass hay fed i s
g iv en in Table 8 and th e com position o f th e grain m ixture fed i s given
i n Table 9 .

56

Table 8 .
Animals used and q u a n titie s o f fee d fed during the d ig e s t io n t r i a l s
Animal

Orchard grass hay

No. 86 grain

X54 *

20 lbs*

7 lb s .

X65 **

25 l b s .

5 lb s .

2408

26 l b s .

9 lb s .

N635

16 lb s .

7 lb s .

* Used w ith sta g e 4 hay o n ly .
** Not used w ith stage 4 hay.

Table 9.
Composition o f No. 8 6 Grain Mixture
Ground Corn

97 p a r ts .

Bone meal

2 p a r ts.

S a lt

1 p a r t.

Chromium oxid e was added to the grain m ixture by m ixing 15 percent
chromium oxid e w ith wheat flo u r and baking in to a hard bread which was
d ried and ground through a medium mesh screen in a w ile y m ill and then
mixed w ith each in d iv id u a l cows r a tio n in amounts th a t would give d a ily
in ta k e s o f approxim ately 15 grams o f chromium oxide per cow.
The fe e d in g schedule fo r th e d if f e r e n t sta g e s o f orchard grass hay
i s g iv en in Table 10*

57

Table 10.
Feeding Schedule o f "the Orchard Grass Hay Cut a t Various S tages
©f M aturity
Dates ( in c lu s iv e )

P eriod

1-24-50 to 2-2-50

P relim inary P eriod

2-3-50 to 2-13-50

Experim ental Period

Stage 4 Orchard Grass
«
B
tt
It

2-14-50 to 2-22-50

P relim inary Period

Stage 3 Orchard Grass

2-23-50 t© 3-4-50

Experim ental P eriod

3-5-50 to 3-14-50

P relim inary Period

3-16-50 to 3-25-50

Experim ental Period

3-26-60 to 4 -4 -5 0

P relim inary P eriod

4-5-50 to 4-1 4 -5 0

Experim ental Period

M aterial Fed

M

II

tt

B

Stage 2 Orchard Grass
ft

«

n

it

Stage 1

n

n

»

it

it

tt

During each 10 day experim ental period d a ily a liq u o ts o f fe c e s sam­
p le s -were c o lle c t e d in d u p lic a te as fo llo w s ; ( 1 ) d ried to con stan t w eight
in a c ir c u la t in g a ir sample d r ie r fo r d a ily determ inations o f dry m atter
eon ten t and ooznposited fo r th e 10 day p eriod fo r chem ical a n a ly s is .

( 2)

fro z en d a ily and composited fo r th e l o day period fo r determ ination o f the
p la n t pigm ent c o n c en tr a tio n , and (3 ) composited in concentrated s u lfu r ic
a cid fo r n itr o g e n d eterm in a tio n s.

Two samples o f the hay fed d a ily were

c o lle c t e d in d u p lic a te as ( 1 ) a 200 gram sample dried to con stan t w eight
f o r d eterm in ation o f th e dry matter con ten t and conxposited fo r the 10 day
p eriod f o r chem ical a n a ly s is , and ( 2 ) a d a ily sample composited as fed fo r
d eterm in ation o f the p la n t pigment c o n cen tra tio n .
Two samples o f a d a ily a liq u o te o f th e urine were c o lle c t e d in du­
p lic a t e and sto red w h ile composited as fo llo w s ;

( 1 ) frozen d a ily fo r

b enzoic a cid d eterm in ation s and ( 2 ) a c id if ie d d a ily w ith d ilu t e (2 0 per­
c e n t) s u lf u r ic acid fo r n itr o g en d eterm in ation s.

D a ily d eterm inations

58

o f th e s p e c i f ic g r a v ity o f "the u rin e and ■total ■volume o f th e u rin e ex creted
were made*

A liq u ote

amounts o f m ilk from each m ilk in g were preserved w ith

formaldehyde and were composited fo r each 10 day period fo r b u tte r fa t
n itr o g e n determ inations*
In a d d itio n to th e d a ily a liq u o te s of the f e c e s , "grab" samples were
taken from two p assages d a ily o f each cow on th ree su c c e ssiv e days during
each te n day experim ental period*

The "grab” samples were taken from two

forenoon and two aftern oon p assages o f f e c e s a t approxim ately the time o f
day th a t had been shown to g iv e rep re sen ta tiv e con cen tration s o f chromium
and l ig n i n in th e f e c e s o f p reviou s t r i a l s (1 0 4 ).

D uplicate samples were

d ried fo r m oisture d eterm in ation s and chem ical a n a ly s is and d u p lica te
samples were fro zen as voided fo r determ ination o f the p la n t pigment con­
c e n tr a tio n w ith th e e x c e p tio n o f th e stage 4 orchard grass hay.

Each

d u p lic a te d a ily grab

sample was handled and analyzed as an in d iv id u a l

sample d esig n a ted as

" f i r s t day p a r t i a l, second day p a r t ia l and th ir d day

p a r tia l" fo r each sta g e o f orchard grass hay fe d .

C orrections were made

fo r th e dry m atter co n ten t o f the "grab" sample to th e t o t a l f e c a l dry
m atter e x cr ete d during the te n day c o lle c t io n period*
The d a te s o f c o ll e c t i o n o f th e "grab" samples are given in Table
11.

59

Table 11
C o lle c tio n D ates o f th e "Grab" Samples taken o f each Stage
__________ ___________ o f Orchard Grass Hay
Orchard Grass

Dates o f F eca l ^ r a b ” Samples
1 s t day

2nd day

3rd day

Stage 1

Apr* 10

Apr* 11

Apr* 12

Stage 2

Mar. 21

Mar* 22

Mar. 23

Stage 3

Feb* 28

Mar. 1

Mar. 2

Stage 4

Feb* 8

Feb. 9

Feb* 10

ANALYTICAL METHODS

Proximate A nalyses
Proximate a n a ly ses o f the fe e d s and f e c e s -were made according to the
procedures d escrib ed by th e A sso c ia tio n o f O f f ic ia l A g r icu ltu ra l Chemists
(7 ) fo r crude p r o te in , eth er e x tr a c t, crude f i b e r , ash and n itr o g e n -fr e e
e x tr a ct*
L ig a in
L ignin was determined by the method o f E l l i s , Mhtrone and Maynard
(6 2 ).
P la n t Pigments
The e x tr a c tio n o f p la n t pigments in the feed and f e c e s were made by
the method o f Reid e t al* (1 5 8 ) but a u n it was a r b it r a r ily d efin ed as th a t
amount o f p la n t pigment per m i l l i l i t e r o f 85 percent acetone e x tr a c t th a t
gave a d e n s ity o f 1*0 w ith a Beckmann model DU spectrophotom eter when read
in a 1 cen tim eter c e ll*

A bsorption curves o f th e e x tr a c ts from the fe c e s

and orchard g ra ss hays were very sim ila r to th ose reported by Reid e t a l
(1 5 8 ) fo r mixed hay and corresponding feces*

60

Chromium
The method used fo r th e determ ination o f chromium oxide was a m o d ifi­
c a tio n o f th e method o f Edin e t e l . (6 1 ).
to 40

S u f fic ie n t sample to co n ta in 20

• o f chromium oxide was weighed in to n ic k e l c r u c ib le s and ashed

u n t i l fr e e o f carbon*

The c r u c ib le s had a volume o f 125 m i l l i l i t e r s , a

h e ig h t o f 6 c e n tim e te r s, suad a diameter o f 6 centim eters*

The ashed ma­

t e r i a l was fu sed w ith a f lu x c o n s is tin g o f 4 grams o f potassium hydroxide,
2*7 grams o f sodium h yd roxid e, and 5*8 grams o f a mixture o f 158 grams
(1 mol) o f potassium carb on ate, 106 grams (1 mol) o f anhydrous sodium ca r­

bon ate, 202 grams (2 mol) o f potassium n i t r a t e , and 170 grams (2 mol) o f
sodium n itr a te *

The totaL 12*5 grams o f the fu s io n m ixture was weighed

o u t and added to each c r u c ib le w ith p recau tion s to lim it the water uptake
o f th e fu s io n mixture*

The c r u c ib le s were then heated on a hot p la te u n t i l

th e m ixture became liq u id and sw irled a t 5 minute in te r v a ls during an add i­
t io n a l h e a tin g period o f 20 minutes*

1/Hhile the m aterial was s t i l l h o t a

n ic k e l w ir e , 1 m illim e te r th ic k and 15 cen tim eters long and formed in to a
s p ir a l a t one end, was p laced in the fused m a te r ia l.

A fter the mass had

s o l i d i f i e d , th e c r u c ib le was q u ick ly heated w ith a g la ss flam e to m elt the
m a teria l around the w a lls so i t cou ld be l i f t e d o u t w ith th e n ic k e l w ir e .
The m elted m a te r ia l was p laced in a 600 m i l l i l i t e r g la s s beaker, th e
c r u c ib le was thoroughly washed w ith warm d i s t i l l e d w ater, and th e washings
tr a n sfe r r e d to th e beaker*
m i l l i l i t e r s o f w ater.

The m a teria l was th en d is so lv e d in 150 to 200

One m i l l i l i t e r o f 30 percent hydrogen peroxide was

added to th e s o lu tio n fo r red u ction o f any 6 v a le n t manganese to th e 4
v a le n t s t a t e .

Mien the s o lu tio n had b o ile d fo r one m inute, i t was f i l t e r e d

through a s in te r e d g la s s f i l t e r fu n n e l in to a 500 m i l l i l i t e r fla t-b o tto m
f la s k in order t o remove the p r e c ip ita te d manganese dioxide*

Then 8*3

61

m i l l i l i t e r o f concen trated s u lfu r ic a cid and 2 .5 m i l l i l i t e r o f hydrogen
peroxid e (30 p ercen t) were added, and th e s o lu tio n heated t o and kept a t
b o ilin g tem perature fo r 5 m inutes in order to d e stro y n i t r i t e s p r e se n t.
When th e s o lu tio n had c o o le d , 2 m i l l i l i t e r s o f hydrogen peroxide (30 per­
c e n t) and 34.5 m i l l i l i t e r s o f 6 .7 5 normal sodium hydroxide -were added and
th e m ixture heated again and b o ile d fo r 5 m inutes to o x id iz e th e reduced
chromium s a l t s to th e chromate*

W ithout in te r r u p tin g the b o ilin g , 5

m i l l i l i t e r s o f 5 p ercen t n ic k e l n it r a t e •were added, and th e b o ilin g was
continued fo r 5 m inutes longer to d estr o y th e ex cess hydrogen p ero x id e.
A fte r c o o lin g , th e s o lu tio n was a c id if ie d slo w ly w ith 1 8 .3 m i l l i l i t e r s
e f concen trated s u lfu r ic a c id , which had been b o ile d p r e v io u sly fo r 4
hours.

When th e s o lu tio n had c o o le d , 10 m i l l i l i t e r s o f th e 10 p ercen t

potassium io d id e s o lu tio n were added and th e s o lu tio n t it r a t e d w ith 0 .0 5
normal sodium t h io s u lf a te u sin g a 1 p ercen t starch so lu tio n as the in ­
d ic a to r .
EXPERIMENTAL RESULTS AND DISCUSSION
The average d a ily dry m atter consumption o f each animal r e c e iv in g the
four sta g e s o f orchard grass hay and the fe c a l dry m atter excreted are g iw n
in Table 12.

The dry m atter consumed in th e grain fed each in d iv id u a l cow

i s th e same fo r each d ig e s tio n t r i a l w hile the dry m atter consumption o f
the v a r io u s sta g e s o f orchard g ra ss hay v a r ie s s l i g h t l y fbr the same a n i­
mal due t o s l i g h t v a r ia tio n s in the dry m atter conten t o f the four sta g es
o f orchard grass hay f e d .

The chem ical com position o f th e grain and the

four sta g e s o f orchard grass hay fed and th e corresponding f e c e s fo r each
anim al used in th e d ig e s t io n t r i a l s i s p resen ted in Table 13.

Each

62

a n a ly s is i s th e average o f a t l e a s t four d eterm inations secured by making
r e p lic a t e a n a ly ses on A and B samples o f eaoh m aterial*

The range in the

sta g e o f m a tu rity rep resen ted by the fou r sta g e s o f orchard grass hay i s
in d ic a te d by the d ecrease in p r o te in con ten t from 24*78 percent to 12*38
p ercen t and th e in c re a se in th e crude fib e r con ten t from 26.88 p ercen t to
35*05 p ercen t w ith in c re a sin g m atu rity.
The apparent d ig e s t io n c o e f f i c i e n t s o f th e c o n stitu e n ts o f the t o t a l
r a tio n c a lc u la te d from the consum ption-excretion r a tio s on samples from
t o t a l f e c a l c o ll e c t i o n are g iv en in Table 14.

I t i s evid en t th a t th ere was

l e s s change in the d i g e s t i b i l i t y o f th e various c o n s titu e n ts between th e
sta g e 1 and 2 orchard grass hays than occurred between th e sta g e s 2, 3 and
4 orchard grass hays*

The apparent d ig e s tio n c o e f f i c i e n t s o f th e vario u s

sta g e s o f th e orchard grass hay alon e were c a lc u la te d by co rrectin g th e
f ig u r e s fo r th e t o t a l r a tio n u sin g th e d ig e s tio n c o e f f i c i e n t s fo r corn
reported fo r c a t t l e by Schneider (161) and are given in Table 15.

A ll o f

th e c o n s titu e n ts o f the proximate a n a ly s is have a con sid erab ly higher d i­
g e s tio n c o e f f i c i e n t in th e orchard grass hay cu t in e a r ly m a tu rity than
in the hay c u t in la t e m aturity*
D ig e stio n c o e f f i c i e n t s were a lso c a lc u la ted f o r the t o t a l c o lle c t io n
samples u s in g the r a tio techn iqu e w ith crude l i ^ i i n , corrected lig n in
(crude lig n in - N itrogen x 6 * 25), chromium oxide and p la n t pigm ents.

Di­

g e s tio n c o e f f i c i e n t s fo r th e in e r t m a ter ia ls rati© tech n iq u es were c a l­
c u la ted from th e fo llo w in g
D ig e stio n
« 100 - 100 X
C o e ffic ie n t

formula:
% In ert m a ter ia l in Feed
% N u trien t in F ec es.
— ------------------------------- X-------------------------------- % In ert M aterial in Feces
% N u trien t in Feed.

The c o n cen tra tio n s o f th e se c o n s titu e n ts in th e fee d s

and fe c e s used fo r

c a lc u la t in g th e d ig e s tio n c o e f f i c i e n t s on the t o t a l c o lle c t io n samples

65

arc g iv en i s Table 16#

The com position o f th e fe c e s c o lle c t e d as ”p a r t ia l

c o l l e c t i o n sam ples” on th ree days o f the te n day t o t a l c o lle c t io n p eriod
and used fo r c a lc u la tio n o f th e d ig e s tio n c o e f f i c i e n t s by the r a tio te c h ­
n iq ues on th e p a r t ia l c o ll e c t i o n samples are given in Table 17#

L ignin

a n a ly s is o f the p a r t ia l c o ll e c t i o n samples were not made sin ce incom plete
r e c o v e r ie s o f lig n in were secured w ith the t o t a l c o lle c t io n samples, thus
g iv in g somewhat low er d ig e s tio n c o e f f i c i e n t s when c a lc u la te d by th e lig n in
r a tio techn iqu e than when c a lc u la te d by th e con ven tion al t o t a l consumptione x c r e tio n r a tio s o f th e variou s c o n stitu e n ts*
The d ig e s tio n c o e f f i c i e n t s o f th e variou s c o n s titu e n ts fo r each in ­
d iv id u a l cow when c a lc u la te d by th e r a tio technique on the t o t a l c o lle c t io n
samples are given in Table 18 and the d ig e s tio n c o e f f i c i e n t s fo r each cow
on each o f the th r ee p a r t ia l c o lle c t io n days c a lc u la te d by th e r a tio tech ­
nique w ith chromium oxide are compiled in Table 19 and when c a lc u la te d by
th e p la n t pigment r a t io technique are given in Table 20.

A summary o f

th e se v a rio u s tech n iq u es o f c a lc u la tin g th e d ig e s tio n c o e f f i c i e n t s i s given
in Table 21, u sin g th e average d ig e s tio n c o e f f i c i e n t s o f the th ree cows
used w ith each stage o f orchard grass hay.

The d ig e s tio n c o e f f i c i e n t s

c a lc u la te d by th e chromium r a tio and pigment r a tio tech n iq u es on both the
t o t a l c o ll e c t i o n samples and the th ree day p a r t ia l c o lle c t io n samples com­
pare very c lo s e ly w ith the standard t o t a l c o lle c t io n technique fo r a l l o f
th e c o n s titu e n ts o f th e proxim ate a n a ly sis*

D ig e stio n c o e f f i c i e n t s c a l­

c u la ted by the l ig n i n r a tio techn iqu e u sin g the crude lig n in co n ten ts o f
th e r a tio n and f e c e s gave s l i g h t l y lower d ig e s tio n c o e f f i c i e n t s than were
o b ta in ed by the t o t a l f e c a l c o lle c t io n technique*

The d ig e s tio n c o e f f i ­

c ie n t s c a lc u la te d by the tru e lig n in rati© technique are s l i g h t l y lower
than th o se c a lc til ated by th e orude l ig n in r a tio tech n iq u e.
A rev iew o f the lit e r a t u r e on variou s d ig e s t io n t r i a l tech n iq u es
in d ic a t e s th a t previou s comparisons o f d ig e s t io n t r i a l tech n iq u es have

64

n o t in clu d ed a comparison o f se v e r a l methods o f determ ining d ig e s t io n co­
e f f i c i e n t s in th e same d ig e s t io n t r i a l .

The p resen t study has made a com­

p a riso n o f seven d if f e r e n t methods o f c a lc u la tin g d ig e s tio n c o e f f i c i e n t s
w ith each o f four d if f e r e n t sta g e s o f orchard grass hay fed w ith a uniform
amount o f g r a in .
A n a ly sis o f varian ce by the method o f Snedecor (169) shows a s i g n i f i ­
cant d iffe r e n c e between th e se seven methods o f c a lc u la tin g d ig e s tio n co­
e f f i c ie n t s *

There i s a c lo s e check, however, between th e d ig e s tio n co­

e f f i c i e n t s c a lc u la te d by the standard t o t a l f e c a l c o ll e c t i o n , the chromium
r a t i o , and th e p la n t pigment r a tio techniques*

The r e s u lt s showed th a t

th e f e c a l r e c o v e r ie s o f lig n in . are somewhat l e s s than 100 p ercen t which
gave lower d ig e s tio n c o e f f i c i e n t s c a lc u la te d "by the lig n in r a tio technique
than th o se obtained by the t o t a l f e c a l c o lle c t io n tech n iq u e.

Further

s tu d ie s would be n ecessa ry to a sc e r ta in i f th e d i g e s t i b i l i t y o f l ig n in
in orchard grass hay i s due to d iffe r e n c e s in the nature o f th e lig n in
is o la t e d from th e fe e d and f e c e s stu d ied ; whether the m etabolism o f lig n in
in orchard grass hay i s d if f e r e n t than lig n in m etabolism in some oth er
p la n ts ; or i f lig n in m etabolism o f second growth orchard grass hay m ight
be d if f e r e n t t l » n th a t o f a f i r s t growth o f the p la n t.

S a tis fa c to r y re­

s u lt s w ith th e l ig n in r a tio method o f c a lc u la tin g d ig e s tio n c o e f f i c i e n t s
have been reported f o r oth er r a tio n s (6 2 , 69, 71, 103, 178)*
The dry m atter d i g e s t i b i l i t i e s o f the r a tio n s co n ta in in g Stage 1 and
Stage 2 hays were sim ila r (Table 2 1 ).

The s l i g h t l y h igh er dry m atter d i­

g e s t i b i l i t y o f the Stage 2 hay compared w ith th e Stage 1 hay was accompanied
by a d ecrease in th e lig n in c o n te n t.

The Stage 2 hay was presumably cu t

during th e period o f th e most rapid rate o f growth o f th e g ra ss.

Huffman

( 9 3 ) has p oin ted out th a t the decreased d i g e s t i b i l i t y o f th e dry m atter

65

o f p la n ts i s b e lie v e d to be a ss o c ia te d w ith l i g n i f i c a t i o n o f the c e l l w a ll
although th e t o t a l amount o f lig n in does not appear to be the determ ining
fa cto r .
The apparent d i g e s t i b i l i t y o f th e crude p r o te in and crude f ib e r was
h igh er in th e r a tio n co n ta in in g Stage 1 orchard grass than in th e r a tio n
co n ta in in g Stage 2 orchard grass but th e d i g e s t i b i l i t i e s o f the n itr o g e n fr e e e x tr a c ts were s im ila r .

D i g e s t i b i li t y o f the dry m atter, p r o te in ,

crude f i b e r , and n itr o g en —fr e e e x tr a c t fr a c tio n s decreased p r o g r e s s iv e ly
in th e Stage 2 , Stage 5 and Stage 4 orchard grass h ays.
SUMMARY
A comparison o f seven d if f e r e n t methods o f determ ining d i g e s t i b i l i t y
c o e f f i c i e n t s was made w ith each of four d ig e s t io n t r i a l s u s in g th ree m ilk in g cows fe d orchard grass hay cu t a t fou r sta g e s o f m atu rity and a sim ple
grain m ix tu re.

The con ven tion al te n day t o t a l f e c a l c o lle c t io n method was

used as a standard fo r comparison w ith th e r e s u lt s of the oth er te c h n iq u es.
Chromium o x id e was added to th e grain r a tio n as an exogenous in e r t sub­
sta n c e .

L ignin and c e r ta in p la n t pigm ents were determined as in e r t ma­

t e r i a l s norm ally p resen t i n th e r a tio n .

The con cen tration s o f th e se th r ee

in e r t m a te r ia ls in the r a tio n fed and in th e f e c a l samples taken from an
a liq u o te o f the t o t a l c o ll e c t i o n were used in c a lc u la tin g th e d ig e s tio n
c o e f f i c i e n t s by th e in e r t m a ter ia l r a tio tech n iq u e.

A d d ition al "grab"

samples tak en on th ree days o f th e ten day c o lle c t io n period were analyzed
and th e d ig e s tio n c o e f f i c i e n t s c a lc u la te d on each o f th ese days by the
chromium r a tio and p la n t pigment r a tio tech n iq u es.

Incomplete r e c o v e r ie s

o f lig n in w ith each o f the t o t a l c o lle c t io n t r i a l s made i t im p ra ctica l to
c a lc u la t e th e d ig e s t io n c o e f f i c i e n t s by th e lig n in r a tio technique w ith
th e "grab" sam ples.

66

Comparable d ig e s t io n c o e f f i c i e n t s were secured w ith th e standard ben
day con su m p tion -excretion method and th e chromium and p la n t pigment r a tio
tech n iq u es when c a lc u la te d w ith both th e t o t a l c o lle c t io n samples aid the
averages o f th r ee days p a r t i a l c o ll e c t i o n or "grab” samples.
D ig e stio n c o e f f i c i e n t s c a lc u la te d by the crude lig n in and the co rrected
l ig n in r a tio tech n iq u es u s in g the t o t a l f e c a l c o lle c t io n samples were both
s i g n if i c a n t ly lower than th e d ig e s tio n c o e f f i c i e n t s c a lc u la te d by th e sta n ­
dard cen su m p tion -excretion method in th e se t r i a l s .
The change in chem ical com position o f the orchard grass hay w ith in ­
c r e a sin g m a tu rity r e su lte d in a d ecrease in p r o te in content o f from 24.78
t© 12.58 p ercen t and an in c r e a se in crude fib e r conten t o f from 26.88 to
3 5 .0 5 p e r c e n t.
D i g e s t i b i l i t y o f th e variou s c o n s titu e n ts in th e four sta g e s o f
orchard grass hay o f in c r e a sin g m aturity was; dry m atter 6 9 .0 , 7 0 .4 ,
6 5 .9 and 5 9 .4 p ercen t; p r o te in , 6 5 .7 , 6 0 .7 , 5 5 .4 and 54.3 p ercen t; crude
f i b e r , 8 2 .5 , 7 8 .6 , 7 2 .0 and 69.1 p ercen t; and n itr o g e n -fr e e e x tr a c t,
6 9 .3 , 7 4 .7 , 6 8 .0 , and 5 7 .3 p ercen t r e s p e c tiv e ly .

67

LITERATURE CITED

1*

Andersen, A* C.
D ie F u tte r m itte la n a ly se und d ie Bestimmung der V erd a u lich k eit
der F u tte r m itte l. Skand. Arch. P h y sio l* , 6 9 :3 3 -5 8 , 1934*

2.

Andersen, A* C*, and L* Frederiksen*
V erd au lioh k eitsversu ch e an Milohkuhen* Biedermanns Z entralbl*
T* Agri cu lt u r chemie u* r a t i one l ie n L a n d w irtsch a ftsb etr., 5 : 3 3 4 ,
1935.

3*

Andersen, A* C. , and J* E* W inther,
F o r d /je lig h e d s fo r s /g med M alkek/er, i l l Gm Be stemmelse a f
Ford^Qelighed ved Edins saak aldte nLedkropps M etode.” Ber,
F o r e /g sla b . (Copenhagen), 155:117-186, 1934*

4*

A rm itage, B* R ., R. Ashworth and W. S* Ferguson.
D eterm ination o f lig n in in p lan t m a te r ia ls o f high p r o te in con­
t e n t . J* Soe. Chem. I n d ., (London), 67:241-243, 1948.

5.

Armsby, H. P*
The n u t r it io n o f Farm Anim als.

The Macmillan Co. New York. 1917.

6*

Armstrong, D* G ,, H. Cook and B. Thomas.
The lig n in and c e llu lo s e co n ten ts o f c e r ta in grassland s p e c ie s
a t d if f e r e n t sta g e s o f growth. J. A g r., S o i . , 4 0 :9 3 -9 9 , 1950.

7.

A s so c ia tio n o f O f f ic ia l A g ricu ltu ra l Chem ists.
O f f i c i a l Methods o f A n alysis o f th e A sso c ia tio n o f O f f io ia l
Agr icupEura 1 cHeinTsts^ Washington, 4 , D. C, 7tTT""Ed. 1950.

8.

Axe I s son, J.
The s c i e n t i f i c b a s is o f sta rch v a lu e . (Trans, t i t l e . )
Biedermanns Z e n tr a lb l. (B) Tiernahrung. 11:176-205, 1939.
Seen in a b str a c t only* N u tr itio n A b stracts & R e v s., 9 :7 6 2 ,
1940.

9.

A xeIsson, J.
Bedeutung und Wert der Rohfaser Fur das F utter des R indes.
Biedermanns Z e n tr a lb l. (B) Tiernahrung, 12:414-443, 1940.

10.

A xeIsson , J.
The f ib e r co n ten t o f th e dry m atter and th e e f f e c t o f the nu­
trim ent in the fodder o f dom estic anim als. (T rans, t i t l e ) .
K gl. Lantbruksakad* T id s k r ., 79:334-344, 1940. Seen in ab­
s t r a c t o n ly . N u tr itio n A b stracts & R e v s., 12:504, 1943.

11*

A x elsso n , J.
The d ig e s t iv e c a p a c ity o f ruminants. (Trans, t i t l e ) . B ieder­
manns Z e n tr a lb l. (B) Tiernahrung. 14:212-232, 1942. Seen in
a b s tr a c t o n ly . N u tr itio n A b stracts & R e v s., 12:684, 1943.

68

18

.

A xel sso n , J.
The a n a ly s is and determ ination o f th e value o f p a stu r e. (T rans,
t i t l e ) . Svenska V a il. o . M osskulturf. K vartalssk r. 5:3 8 0 -3 9 2 ,
1942. Seen in a b stra ct o n ly . N u tr itio n A b stra cts A R e v s.,
1 3 :527, 1944.

13.

A xeIsson , J .
The a b i l i t y o f c a t t l e , sheep, h orses and swine to d ig e s t th e
n u tr ie n ts o f the fe e d in g s t u f f s . Ann. Roy. Agr. C o ll. Sweden,
16*84-100, 1949.

14.

A x e lsso n , J.
Connections between c o n ten ts o f n u tr ie n ts and d i g e s t i b i l i t y o f
grassland crop s. Kgl* Lantbruks-Hogskol. Ann., 17:320-341, 1950.

15.

A x elsso n , J . , and S . E rik sson .
Comparison between th e a ccu ra cies o f th e d ir e c t and in d ir e c t
methods in d ig e s tio n t r i a l s w ith rum inants. K gl. Lantbruks.Hogsk. Arm., 17*375-395, 1950.

16.

A x e lsso n , J . , and S. E rik sson .
The a v a i l a b i l i t y o f the method o f determ ination by d iffe r e n c e o f
th e e f f e o t o f in d iv id u a l fe e d s . Some treatm ent o f the d a ta o f
European m etab olic experim ents w ith growing p ig s . Kgl. LantbruksHogsk. Ann., 17*161-203, 1950.

17.

A x elsso n , J», and A. Kivimae*
Comparison between the a ccu racies o f the d ir e c t and in d ir e c t
methods in d ig e s tio n t r i a l s w ith w eth ers. Acta Agr. Soandinavica,
1 :2 8 2 -2 9 0 , 1951.

18.

Baker, F . , and S . T. H a r r iss.
M icrobial d ig e s tio n in the rumen (and caecum) w ith s p e c ia l r e fe r ­
ence t o th e decom position o f str u c tu r a l c e l lu l o s e . N u tr itio n
A b stra cts & R e v s., 1 7 :3 -1 2 , 1947.

19.

B arniooat, C. R.
E stim ation o f apparent d i g e s t i b i l i t y c o e f f i c i e n t s by means o f an
in e r t "referen ce - su bstance”. N* Zealand J. Sci* T ech ., 27;
202-212, 1945.

20

.

21

M. C ., C.
. B e ll , The
e ffe c t

B e l l , M. C ., C. K. TSIhitehair ani W. D. G allup.
The e f f e c t o f aureomycin on d ig e s tio n in s t e e r s .
9*647-648, 1950.
K. HEhitehair and W. D. G allup.
o f aureomycin on d ig e s tio n in s t e e r s .
Expt. B io l. Med., 76:284-286, 1951.

O la f.
. Bergeim,
I n t e s t in a l

22

J. Animal

S c i.,

Proc* Soc.

Chem istry. IV. A method for the study o f food u t i l i ­
z a tio n or d i g e s t i b i l i t y . J. B io l. Chem., 70*29-34, 1926.

69

23.

Bergeim, O la f.
I n t e s t in a l Chemistry* V. Carbohydrates and calcium and phos­
phorus m etabolism . J. B io l. Chem., 70:3 5 -4 5 , 1926.

24*

Bergeim, O la f.
I n t e s t in a l Chem istry. V I. A method fo r the study o f absorp tion
i n d if f e r e n t p a r ts o f th e g a s tr o in te s tin a l t r a c t . J, B io l.
Chem., 7 0 :4 7 -5 0 , 1926.

25*

Bergeim, O la f.
I n t e s t in a l Chem istry. V II. The absorp tion o f calcium and
phosphorus in th e sm all and la r g e in te s t in e s * J. B io l. Chem.,
70*51-58, 1926.

26.

B la x te r , K. L. and H. H. M itc h e ll.
The f a c t o r iz a t io n o f th e p r o te in requirem ents o f ruminants and
o f th e p r o tein v a lu e s o f f e e d s , “with p a r tic u la r referen ce to
th e s ig n ific a n c e o f the m etab olic f e c a l nitrogen* J . Animal
S c i . , 7:351-372, 1948.

27.

Bondi, A. H. and H. Meyer.
On th e chem ical nature and d i g e s t i b i l i t y o f roughage carbo­
h y d ra tes. J. Agr. S c i . , 33:123-128, 1943.

28*

Bondi, A. H. and H. Meyer.
Li gain s in young p la n ts .

Biochem. J . , 43:248-256, 1948.

29*

B u r k itt, W. H.
The apparent d i g e s t i b i l i t y and n u tr itiv e valu e o f b ea rd less
•wheatgrass a t th ree sta g es o f m atu rity. J . Agr. R esearch,
61*471-479, 1940.

30.

Burroughs* W., Norma A. Frank, P . Gerlaugh and R* M. Bethke.
P relim in ary o b ser v a tio n s upon fa c to r s in flu e n c in g c e llu lo s e
d ig e s t io n by rumen m icroorganism s. J . N u tr itio n , 40*9-24,
1950.

31.

Burroughs, W., L. S. G a ll, P. Ger laugh and R. M. Bethke.
The in flu e n c e o f c a s e in upon roughage d ig e s tio n in c a t t l e
w ith rumen b a c te r ia l s tu d ie s . J. Animal S c i . , 9*214-220,
1950.

32.

Burroughs, W*, and P. Gerlaugh.
The in flu e n c e o f soybean o i l meal upon roughage d ig e s t io n
in c a t t l e . J. Animal S c i . , 8 :3 - 8 , 1949.

33.

Burroughs, W., P. Gerlaugh and R. M. Bethke.
The in flu e n c e o f a l f a l f a hay and fr a c tio n s o f a l f a l f a hay
upon th e d ig e s tio n o f ground corncobs. J. A n im a l S c i . , 9:
207-213, 1950.
Burroughs, W., P. G erlau ^ i, B. H. Edgingtom and R. M. Bethke.
Further o b ser v a tio n s on th e e f f e c t o f p r o te in upon roughage
d ig e s t io n in c a t t le * J . Animal S c i . , 8 * 9 -1 8 , 1949.

34.

70

95.

Burroughs, W., H. G. H eadley, R. M. Bethke, aid p* Gerlaugh*
C e llu lo se d ig e s tio n in good and poor q u a lity roughages u s in g
an a r t i f i c i a l rumen. J. Animal S c i* , 9*513-522, 1950.

36.

Burroughs,
, J* Long, P* Gerlaugh and R* M* Bethke*
C e llu lo s e d ig e s tio n t y rumen microorganisms as in flu e n c ed "by
c e r e a l g ra in s and p r o te in ric h fe e d s commonly fed to c a t t l e
u sin g an a r t i f i c i a l rumen* J. Animal S c i ., 9*523-530, 1950.

37*

Chanda, R*, Helen Iff. Clapham, Mary L* McNaugbfc and E . C. Owen.
The use o f chromium sesq u ioxid e t o measure th e d i g e s t i b i l i t y
o f carotene by goats and cows* J . Agr* S c i . , 41*179-186, 1951.

38*

C olovos, N. F*, H* A* Keener, J. R. P r e sc o tt and A* E. Teeri*
The n u t r it iv e valu e o f tim othy hay a t d if f e r e n t sta g e s o f ma­
t u r it y as compared -with second c u ttin g clover hay. J. D airy
S c i . , 32*659-664, 1949.

39*

Committee o f American S o c ie t ie s o f Agronomy, Dairy S c ie n c e , Animal
P rod u ction , and Range Management*
Report on p asture and range research tech n iq u e. Mimeo. 1950*

40*

Cook, C. W., and I», E* Harris*
A comparison o f th e l ig n i n r a tio technique and the chrome gen
method o f determ ining d i g e s t i b i l i t y and forage consumption o f
d e se r t range p la n ts by sheep* J. Animal S c i* , 10*565-573, 1951.

41*

C orbin, J. E*
Unpublished t h e s i s , Univ. o f Kentucky, 1947* C ited by F orbes,
R. M., and W. P* G arrigus. J. Animal S c i* , 7*37o-382, 1948*

42.

Corbin, J . E*, and R* M* Forbes*
Dye as a referen ce m a teria l for determ ining th e d i g e s t i b i l i t y
o f a r a tio n w ith lambs* J* Animal S c i* , 10*574-580, 1951*

43*

Crampton, E. W.
pasture stu d ies* XIV. The n u t r it iv e value o f pasture herbage*
Some problems i n i t s e stim a tio n and seme r e s u lt s thu s fa r ob­
ta in e d a t MacDonald C o lleg e . Sci* Agr*, 19*345-357, 1939*

44*

Crampton, E. W. and I . R. C. Jackson*
P asture stu d ies* XXVI. Seasonal v a r ia tio n in chemical com­
p o s itio n o f p asture herbage and th e r e la t io n t o i t s d i g e s t i ­
b i l i t y by s te e r s and sheep* J. Animal S c i* , 3*333-339, 1944.

45.

Crampton, E* W. and L. E* Lloyd*
S tu d ie s w ith shaep on th e use o f chromic oxid e as an ind ex o f
d i g e s t i b i l i t y o f ruminant r a tio n s . J. N u tr itio n , 45*319-327,
1951.

46*

Crampton,
W. and L* A* Maynard*
The r e la t io n o f c e llu lo s e and lig n in conten t to the n u t r it iv e
valu e o f animal fe e d s . J. N u tr itio n , 15*383-395, 1938*

71

47*

Crampton, E. W. and F. W hiting.
A proposed scheme o f feed in g s t u f f s a n a ly s is .
2*278-284, 1942.

J. Animal S o i .,

48.

Csonka, F. A ., M. P h illip s and D. B. Jones.
S tu d ies on lig n in m etabolism . J. B io l. Chem., 85*65-75, 1929.

49.

D a n ie l, T. W*, f . b . Wolberg, V. L. M ille r , J. H. Alswager, M. E.
Ensminger, and A. A. Spielman*
Chemical com position and d i g e s t i b i l i t y o f f l a t pea forage in
th ree s ta g e s o f m a tu rity . J. Animal S o i ., 5 :8 0 -8 6 , 1946.

5u*

D a v is, R. E ., C. 0 . M illar and I . L. L indahl.
Apparent d i g e s t i b i l i t y by sheep o f lig n in in (dehydrated) pea
and lim a bean v in e s . J . Agr. R esearch, 74:285-288, 1947.

51.

Dawson, J. R. , D. ¥• Kopland and R. R. Graves.
Y ie ld , chem ical com p osition, and feed in g value fo r m ilk pro­
d u ctio n o f a l f a l f a hay cu t a t th ree sta g es o f m atu rity.
U.S.D .A . Tech. B u ll. 759, O ct. 1940.

52.

DeMan, T. J . , and J . G. DeHeus.
L ignin in grass (w ith sp e c ia l referen ce to the n itro g en p r e sen t
in the l i g a i n p r e p a r a tio n ). Rec. Trav* Chim. P a y s-B a s., 69:
270-276, 1950.

53.

D ijk s tr a , N. D.
The d i g e s t i b i l i t y and feed in g valu e o f a r t i f i c i a l l y d ried g r a ss.
(T rans, t i t l e ) . V e r s l. Landbouk. Onderzoek., 1949. Seen in
a b stra c t o n ly . N u tr itio n A b stra cts & R e v s., 20:208-209, 1950.

54.

D ijk s tr a , N. D. and E. Brouwer.
D i g e s t i b i l i t y and feed in g value o f grass mowed a t d if f e r e n t
p e r io d s. V e rsla g . Landb. O nderzoek., No. 45, C, 1 -4 5 , 1959.

55.

D rapala, W. J . , L. C. Raymond and E. W. Crampton.
p astu re S tu d ie s. XXVII. The e f f e c t s o f m aturity o f the p la n t
and i t s l i g n i f i o a t i o n and subsequent d i g e s t i b i l i t y by anim als
as in d ic a ted by methods o f p lan t h is to lo g y . S c i. A gr., 27:
5 6 -41, 1947.

56.

Druce, E ., and J . S . W ill cox.
The a p p lic a tio n o f m odified procedures in d i g e s t i b i l i t y s tu d ie s .
Empire J . Expt. A g r ., 17:188-192, 1949.

67.

Duckworth, J.
A s t a t i s t i c a l comparison o f the in flu e n c e o f crude f ib e r on th e
d i g e s t i b i l i t y o f roughage by bos in d iou s (zebu) and bos taurus
c a t t l e . Trop. A g r ., (T rin id a d ), 2 3 :4 -8 , 1946.

58.

Dunlop, A. A ., and M. R. Coup.
The n u t r it iv e value o f pampas grass (C ortaderia S e llo a n a ),
N. Zealand J. S c i. T ech ., 32A:21-34, 1951.

72

59.

E din, H.
O rienterande ferso k over en pa ledkropp sp in cip en grundad metod
a t t bestamma en faderblandnings sm altbarhet. Medd. Nr. 105
fr a n . C en tralan st. For Forsoksvasendet pa Jordbruksomradei.
1918.

60.

Edin, H.
F o r ts a tta fo rso k med in d ir e k ta pa "ledkroppsprincipen" grundade
meto der fo r b e s t sinning av fo d r e ts sm altbarhet. C en tralan st. F.
F orsoksvas. pa jordb.-orar. Medd. 3 0 9 :1 -7 9 , 1926.

61.

Edi n , E ., 0 . K ihlen and S . N o rd feld t.
A summarised d e s c r ip tio n o f 1*Ediii, s in d ic a to r method1* fo r the
determ in ation o f th e d i g e s t i b i l i t y o f fe e d s and feed m ixtu res.
Lantbruks. H ogskol. Ann. 12:166-171, 1944-45.

62.

E l l i s , 6 . H ., 9 . Matrons and L. A. Maynard.
A 72-p ercen t H2SO4 method fo r th e determ ination o f lig n in and
i t s u se in animal n u tr itio n s tu d ie s . J. Animal S o i . , 5 :2 8 5 - 2 9 7 ,
1946.

65.

E rikksson, S.
D ig e stio n experim ents w ith d ried b eet food m ixture.
Agr. C o ll. Sweden, 16:167-178, 1949.

Ann. Hoy.

64.

Ewing, P . V. and F. H. Sm ith.
D i g e s t i b i l i t y o f corn s ila g e , v e lv e t-b e a n meal and a l f a l f a hay
when fe d s in g ly and in com binations. J. Agr. Research, 13:
611-618, 1918.

65.

Ewing, p . V. and C. A» We11s.
The a s s o c ia tiv e d i g e s t i b i l i t y o f corn s i l a g e , co tto n seed meal
and sta r ch on s te e r r a tio n s . Ga. Agr. Expt. S ta . B u ll. 115,
1915.

66

.

Ferguson, W. S.
The d i g e s t i b i l i t y o f wheat straw and wheat straw p u lp .
J . , 36:786-789, 1942.

Biochem.

67.

Forbes, K. M.
Some d i f f i c u l t i e s in volved in th e use o f f e c a l n itr o g e n as a
measure o f d ry m atter in tak e o f grazing anim als. J. Animal
S c i . , 8 :1 9 -2 5 , 1949.

68*

F orb es, E. B ., R. F. E l l i o t , R. W. S w ift, W. H. James and V ivian
F* Sm ith.
V a r ia tio n in determ inations o f d ig e s tiv e c a p a c ity o f sheep.
J. Animal S c i . , 5 :2 98-305, 1946.

69.

Forbes, R. M. and W. P . G arrigus.
The d i g e s t i b i l i t y and m e ta b o liz a b ility by lambs o f a standard
r a tio n o f a l f a l f a and co m and one con tain in g cotton seed h u l ls .
J* Agr. R esearch, 78:48^-488, 1949.

73

70.

F orbes, R. M. and W. P. Garrigus*
Some r e la tio n s h ip s between chem ical com p osition , n u t r it iv e v a lu e ,
and in ta k e o f fo ra g es grazed by s te e r s and wethers* J. Animal
S o i . , 9 s 354*362, 1950.

71.

F orbes, R. M ., and W. p . G arrigus.
Seme e f f e c t s o f forage com position on i t s n u tr itiv e va lu e when
ou t and fe d green to s te e r s and w eth ers, as determined conven­
t i o n a l l y and by th e lig n in r a t i o . J . Animal S o i . , 9;5 3 1 -5 3 9 ,
1950.

72.

F orb es, E. B ., and R. W. S w ift.
C onditions a f f e c t in g th e d i g e s t i b i l i t y and the m etab olizab le
energy o f fe e d s f o r c a t t l e , p a. Agr. Expt. S ta . B u ll. 452,
S ep t. 1943.

73.

F o s te r , L ., and L. A. M e r r ill.
A lf a lf a or lu cern es The c u ttin g tim e. I t s fee d in g v a lu e .
Utah Agr. E xpt. S ta . B u ll. 61, 155-214, 1899.

74.

F ra n co is, A.
The erro r committed in th e c a lc u la tio n o f th e forage valu e o f
a com posite n u tr ie n t as a fu n c tio n o f errors from chem ical
a n a ly s is . Ann. A gren., 19 $452-465, 1949.

75.

F ra n co is, A ., A* M. Leroy and Genevieve Levy.
The f a t e o f methexy groups during d ig e s tio n o f p e c tin and
l ig n in by ruminants. Coxopt. r e n d ., 232$132S-1325, 1951.

76.

G allup, W. I).
The d i g e s t i b i l i t y o f th e p r o te in s o f some cotton seed p rod u cts.
J . B io l. Chem., 76s43—53, 1927.

77.

G allup, W. D.
A note on th e determ ination o f the d i g e s t i b i l i t y o f p r o te in
by B ergeim 's method. J . B ie l. Chem., 81:321-324, 1929#

78.

G allu p , W. D ., and E. M. B riggs.
The apparent d i g e s t i b i l i t y o f p r a ir ie hay o f v a r ia b le p r o te in
c o n ten t, w ith some o b serv a tio n s o f fe c a l n itro g en e x c r e tio n by
s te e r s in r e la t io n to th e ir dry m atter intake* J* Animal S o i .,
7:1 1 0 -1 1 6 , 1948.

79.

G allup, W. D ., C. S. Hobbs and H. M. B riggs.
The use o f s i l i c a a s a referen ce substance in d ig e s tio n t r i a l s
w ith rum inants. J . Animal S c i . , 4 :6 8 -7 1 , 1945.

80.

G a llu p , W. D ., and A. H, Euhlmsn.
A p relim in ary study o f th e determ ination o f th e apparent d ig e s t ­
i b i l i t y o f p r o te in by m odified procedures. J . Agr. Research,
42:665-669, 1931.

81.

G allu p, W. D ., and A. H. Kuhlman.
The con$>osition and d i g e s t i b i l i t y o f mung-bean s ila g e w ith ob ser­
v a tio n s on the s i l i c a - r a t i o procedure fo r studying d i g e s t i b i l i t y .
J . Agr. R esearch, 52:889-894, 1936.

74

82.

G raves, B. R ., «J. R. Dawson, D. V. Kopland, A. L. "Watt and A. G*
Van Horn.
Feeding cows on a l f a l f a hay a lo n e. U.S.D.A. Tech. B a ll. 610:
1 -4 6 , 1938.

83.

Gray, F . v .
The d ig e s tio n o f c e llu lo s e by sheep. The e x te n t o f c e llu lo s e
d ig e s tio n a t su c c e ssiv e l e v e l s o f th e alim entary t r a c t . J.
E xpt. B i o l . , 24:15-19, 1947.

84.

H ale, E* B ., C. W. Duncan and C* F. Huffman.
Rumen d ig e s tio n in the bovine w ith some ob servation s on th e
d i g e s t i b i l i t y o f a l f a l f a hay. J . Dairy S c i . , 23:953-967, 1940.

85.

H allsw orth , E. G.
The r e la tio n s h ip between the crude fib r e content o f pasture and
e th e r f e e d in g - s t u f f s and t h e ir d i g e s t i b i l i t y and sta r ch eq u iv­
a le n t . J. Agr. S c i . , 39:254-258, 1949.

86.

Ham ilton, T. S . , H. H. M itc h e ll and W. G. Kammlade.
The d i g e s t i b i l i t y and m etab olizab le energy o f soybean products
fo r sheep. 111. Agr. Expt. S ta. B u ll. 303, 1928.

87.

Ham ilton, T. S . , H. H. M itc h e ll, C. H. Kick and G. G. Gannen.
Hew methods t e s t e d in d ig e s tio n t r i a l s . 4 1 st Ann. Rpt. 111.
Agr. Expt. S t a ., 119-121, 1927-28.

88

.

Hawley, L. F ., and A. G. Roman.
The d if f e r e n t ia t io n o f h e m io e llu lc s e s .
1190-1194, 1932.

Ind. Eng. Chem., 24:

89.

Headden, W. P.
A study o f a l f a l f a and some o th er hays.
B u ll. 39, 1897.

90.

H e lle r , V. G ., C#
A comparison
c o e ffic ie n ts
B io l. Chem.,

91.

Henmeberg, J . W. J. and F. Stohmann.
B eitrage zur Begrundung e in er r a tio n e lle n Futterung der
Nbiderkauer. Braunschweig, He f t a 1 und 2 , 1860-1864.

9 2.

Homb, T.
The con n ection between the con ten t o f lig n in and d i g e s t i b i l i t y
in animal f e e d s . (Trans, t i t l e ) . Norges Landbfuksh/rfgsk.
F o r in g s fo r s /k . No. 6 1 :1 -4 8 , 1946. Seen in a b str a c t o n ly .
N u tr itio n A b stracts & R e v s., 19:470, 1949.

93.

Huffman, C. F.
Roughage q u a lity and q u a n tity in the d airy r a tio n , a review .
J . Dairy S c i . , 22:889-980, 1939.

C olo. Agr. E xpt. S ta .

H. Breedlove and W. L ik e ly .
o f the Bergeim and standard methods of determining;
o f u t i l i z a t i o n w ith suggested m o d ific a tio n s. J .
79:275-282, 1928.

75

94.

Hungate, R. E.
The anaerobic m esop h ilic o e ll u l o l y t ic b a c te r ia .
14*1-49, 1950.

B act. R e v s.,

95.

H v id sten , H.
Experiments w ith o e llu lo s e fo r rum inants. (Trans, t i t l e ) .
Meld. Norges Landbruksh/gsk. 26*63-254, 1946. Seen i n ab­
s t r a c t o n ly . N u tr itio n A b stracts A R e v s., 17*265, 1947.

96 .

Irw in , M. I . , and E. W. Crampton.
The use o f ohromic oxide as an index m a teria l in d ig e s tio n
t r i a l s w ith human s u b je c ts . J . N u tr itio n , 43*77-86, 1951.

97.

Jaequot, R.
L * in d ig e stib le glueidiquo e t l fabsorp tion in te s tin a l© .
A p p lica tio n aux tech n iq u es an a ly tiq u es de l a chim ie alim ent a ir e .
Report to a conferen ce h e ld on 10th Jan. 1946. Lab. Biochem.
R u t ., C .N .R .S ., Seen in a b s tr a c t o n ly . N u tr itio n A b stracts &
R e v s., 18*230, 1948.

98.

J a r l, F.
The e f f e c t o f th e con ten t o f p la n t f ib e r on th e d i g e s t i b i l i t y
and th e n u tr ie n t value o f northern typ es o f hay. (Trans,
t i t l e ) . Nord. Jordbrugsforskning. 20*1-32, 1938. Seen in
a b str a c t o n ly . N u tr itio n A b stracts & R ev s., 9*222, 1939.

99.

J a r l, F.
The accuracy o f Edin* s in d ic a to r method fo r d i g e s t i b i l i t y
experim en ts. K gl. Lantbruks. E ogskol. Ann., 16*785-788, 1949.

.

100

.

101

.

102

J a r l, F.
D i g e s t i b i l i t y t r i a l s w ith c a t t l e . 2. Hay, fo d d er, r o o ts ,
o ilc a k e s and other fe e d s and hay from h a rv estin g t r i a l s a t
A lnays. K gl. Lantbrukshogsk. S ta t . H usdjursforsok Medd.
No. 44*1-60, 1950.
J on es, D. B.
F actors fo r con vertin g p ercentages o f n itro g en in foods and
fe e d s in to p ercen tages o f p r o te in . T7.S.D.A. C iro. 183, 1931.
Kane, E. A ., W. C. Jacobson and L. A. Moore.
D i g e s t i b i l i t y stu d ie s on d a iry c a ttle * A comparison o f the
t o t a l c o ll e c t i o n methods* Conventional versu s chromium oxid e
and lig n in tec h n iq u es. J . Animal S c i . , 3*623, 1949.

10 *5* Kane, E. A ., W. c . Jacobson and L. A. Moore.
A comparison o f tech n iq u es used in d i g e s t i b i l i t y s tu d ie s w ith
d a ir y c a t t l e . J. N u tr itio n , 41*583-596, 1950.
104.

Kane, E. A ., W. C. Jacobson and L. A. Moore.
D iurnal v a r ia tio n in th e e x c r e tio n o f chromium ox id e and
l ig n i n . J. N u tr itio n . In p r e ss.

76

105*

K night, G. H ., P . E. Hepner and G. E. Morton.
D ig e s tio n experim ents w ith w eth ers. Wyo. Agr. Expt. S ta . B u ll.
&9| 1906a

106.

Knotty J . C*, H. K. Murer and R. E. Hodgson.
The d eterm ination o f apparent d i g e s t i b i l i t y by m odified pro­
c ed u res. Proo. 21st Ann. Meeting Western D iv. Amer. Dairy
S c i . A ssoc. 4 7-50, 1935.

107.

K nott, J . C ., H. K. Murer and R« E. Hodgson.
The d eterm ination o f the apparent d i g e s t i b i l i t y o f green and
cured grass by m odified procedures. J . Agr. R esearch, 53 1
553-556, 1936.

106.

K reula, M. S .
A bsorption o f carotene from ca rr o ts in man and the use o f th e
q u a n tita tiv e chromic oxid e in d ic a to r method in absorp tion e x ­
p erim en ts. Bio chem. J . , 41*269-275, 1947.

109.

L a n caster, R. J.
The measurement o f fee d in tak e by grazing c a t t le and sheep, I .
A method o f c a lc u la tin g the d i g e s t i b i l i t y o f pasture based on
th e n itr o g en con ten t o f fe o e s derived from the p a stu r e . N.
Zealand «J* S c i. T ech ., 31A*31—38, 1949.

.

110

.

111

.

L an caster, R. J .
M etabolism t r i a l s w ith Hew Zealand feed in g s t u f f s . IV. The
r e la t iv e s ig n ific a n c e o f lig n in , o e llu lo s e and crude f ib e r in
th e e v a lu a tio n o f fe e d s . N. Zealand J . S c i. T ech ., 25A:137151, 1943.
L an caster, R« J.
E stim ation o f d i g e s t i b i l i t y o f grazed pasture from fe c e s
n itr o g e n . N atu re, 163*330-331, 1949.

112

Lloyd, 1*. E.
The u se o f chromic oxide a s an index o f d i g e s t i b i l i t y o f th e
dry m atter o f a hog r a tio n . Unpublished d a ta , MacDonald C o lle g e ,
C ited by Crampton, E# W., and L* E. L loyd, J. N u tr itio n , 45:319327, 1951.

113.

Louw, J . G.
The r e la t iv e d i g e s t i b i l i t y o f the c o n s titu e n ts o f th e carbo­
hydrate complex o f g ra sses a t su ccessiv e sta g e s o f growth w ith
referen ce to t h e ir p a r t it io n in to crude f ib e r and n itr o g e n -fr e e
e x tr a c t according to th e standard method fo r feed in g s t u f f
a n a ly s is . O nderstepoort J. V et. S c i . , 17:165-179, 1941.

114.

MaoDeugall, D ., and W. A. DeLong.
A study o f methods fo r th e e x tr a c tio n o f n itrogen ous m a teria l
from p la n ts w ith p a r tic u la r referen ce to subsequent determina­
t io n o f the lig n in c o n ten t. Can* J* R esearch, B .26:457-463, 1948.

77

115.

116.

Mangold, E.
The d ig e s tio n and u t i l i z a t i o n o f crude f i b e r .
s t r a c t s <& R e v s., 3:647-656, 1934.
M arsh all, R. A.
The d ig e s tio n o f pentosans in hay by sheep.
3 * 1 -2 , 1949.
*

N u tr itio n Ab­

B r it. J . N u tr itio n ,
9

117.

Matrone, G ., G. H. E l l i s and L* A. Maynard.
A m odified Nom an-Jenkins method fo r the determ ination o f o e l l ­
u lo s e and i t s use in the e v a lu a tio n o f f e e d s t u f f s . J . Animal
S c i . , 5*306-312, 1946.

118.

Maymeme, B ., end M. T ib e rio .
D ie methoden der analyse b e i verd au lich k eitsversu oh en und d ie
s ic h daraus ergebenden v a r ia tio n e n der v e z d a u lio h k e its k o e ffiz ie n te n der roh faser in den F utte r m itte ln . Z. Tierem ahrung
F u tte r m itte lk ., 8*82-96, 1944.

119.

MeA n a lly , r. a .
D ig e stio n o f straw by the ruminant.
1942.

.

120

.

121

.

Bio chem. J . , 36*392-399,

McAnally, R. A ., and A. T. P h illip son.
D ig e stio n in the ruminant. B io l. H ev., 1 9 :41-54, 1944.
MeBee, R. H.
The anaerobic therm ophilic c e l l u l o l y t i c b a c te r ia .
14*51-63, 1950.

B aot. Revs.

122

McCullough*
F. E l li o t and G. M. B a stin .
Use o f the cbrom0 g en (s) technique in the determ ination o f
season al changes in d i g e s t i b i l i t y o f d ry m atter and p r o te in
o f pasture herbage. J. Dairy S o i . , 34*494, 1951.

123.

MoMeekan, C. P.
A note on th e r e la tio n s h ip between crude fib e r and the d ig e s t ­
i b i l i t y o f organic m a tter. N. Zealand J . S c i . , Tech. 25A:152153, 1943.

124.

M il l s , A. A.
A lf a lf a , or lu c er n e .

125.

M itc h e ll, H. H.
The e v a lu a tio n o f fee d s on th e b a sis o f d ig e s t ib le and
m etab olizab le n u tr ie n ts* J. Animal S c i* , 1*159-173, 1942.

126.

M orrison, F. B.
Feeds and Feeding. 2 1 st E d itio n .
P u b lish in g C o., 1948•

127.

Mumford, H. W., H. S. G rin d ley, L. D. H all aid A. D. Emmett.
A study o f the d i g e s t i b i l i t y o f a r a tio n fo r s t e e r s . 111.
Agr. Expt. S ta . B u ll. 172, 1914.

Utah Agr. Expt. S ta . B u ll. 44, 1896.

Ith a ca , N .Y ., The Morrison

78

128.

Naumann, K.
B eitrage zur Ksjaabnis der Verdau 1 ic h k e it der p fla n z lic h e n
Rohfaser und ih r er B estan d teile* Z tschr. Tierernahrung
F u tte r m itte lk ., 3:193-246, 1940.

129.

Newlander, J . A ., h . B. E llen b erg er, 0 . M. Camburn and C. H. Jones.
D i g e s t i b i l i t y o f a l f a l f a , tim oth y, and soybeans as s ila g e s and
as hays. V t. Agr. Expt. S ta . B u ll. 430, 1938.

130.

H o lle r , C. H ., D. L. H ill and H. s. Lundquist.
O bservations on the use o f the chromogen technique in determ ining
forage consumption o f m ilking cows. J. Animal S c i . , 10:1072^1951*

131.

N o r d fe ld t, S . , I . Iwanga, K. M arita, L. Am Henke and Annie K. S . Tom.
In flu en ce o f crude f ib e r in th e r a tio n on e f f i c ie n c y o f fe e d
u t i l i s a t i o n by dairy cows. J . Dairy S o i ., 33:473-485, 1950.

132.

H o rd feld t, S . , 0 . Svanberg ani 0 . Claes son.
A n alysis o f crude f ib e r . Acta Agr. Sueosna, 3:135-177, 1949.

133.

Herman, A. G.
The com position o f crude f ib e r .

134.

J. Agr. S c i . , 25:529-540, 1935.

Norman, A* G.
CXCIXI. The com position o f forage cro p s. 1 . Rye g r a ss,
w o lth s ). Bioohem. J . , 30:1354-1362, 1936.

(iffiastern

135.

Herman, A. G.
The a s s o c ia tio n o f xylan w ith c e llu lo s e in c e r ta in str u c tu r a l
c e l l u l o s e s . Bioohem. J . , 30:2054-2072, 1936.

136.

Norman, A. G.
The Biochem istry o f C e llu lo s e , The P olyu ron id es, L ign in , e t c .
Oxford a t tbe Clarendon iPress, 1937.

137.

Herman, A. G.
Biochem ical approach to grass problem s.
31:751-760, 1939.

138.

Herman, A. G. and W. H. F u lle r .
C e llu lo s e decom position by m icroorganism s.
2:239-264, 1942.

139.

Norman, A. g* and S. H. Jenkins.
The determ in ation Of l ig n i n . I I . Errors introduced by th e
presence o f p r o te in s . Bioohem. J . , 28:2160-2168, 1934.

140.

O lo fsso n , S.
Het energy conten t o f pasture and the r e la tio n sh ip between
crude p r o te in con ten t and feed in g v a lu e . Svenska Bates 0 .
V a llfo r e n . A rsskr. 20:133-148, 1938. Seen in a b stra c t o n ly .
N u tr itio n A b stra cts and Revs. 8 :8 8 2 , 1939.

J. Amor. Soc. A gron.,

Adv. in Enzymology,

79

141.

142.

Olson j F* p . 9 W. H. P etersen and E. C. Sherrard*
E f f e e t o f l ig n i n on ferm en tation o f o o llu lo s ie m a te r ia ls .
Eng. Chem*, 29:1026-1029, 1937.
O lsson , N ., Qm K ihlen and W. C a g e ll.
Sm altbarhetsforsok med ha s t a r . Lantsbrukshogskol.
fo r s o k s a n s ta lt. Medd. 36, 1949.

Ind.

Rusdjurs-

145*

Paloheim o, L.
D ie Verwendung der Saur©hydrolyse zur Li gpinbe stimnrung.
Biochem. Z ., 165:463-464, 1925.

144«

paloheim o, L.
B eitrage zur Ligninbestimmung m it Saurehydrolyse.
214:161-174, 1929.

Bioohem. Z .,

146.

pazur, J . H ., and W. A. DeLong.
P astu re s t u d ie s . XXVTII. E ff e c t o f lig n in con ten t and o f sta g e
o f m aturity o f dry clover forage on th e urinary e x o r e tio n o f
arom atic a e id s by sheep. S o i. A g r., 28:39-46, 1948.

146.

P h i l l i p s , M.
The q u a n tita tiv e determ ination o f m ethoxyl, lig n in and c e l lu ­
lo s e in p la n t m a te r ia l. J. Assoo. O ff. Agr. Chem., 15:118-131,
1932.

147.

P h i l l i p s , M., B. L. Davis and H. D. Weihe.
Composition o f the tops and roots o f the tim othy p la n t a t su c c e ssiv e
sta g e s o f growth. J. Agr. He search , 64: 533-546, 1942.

148.

P h i l l i p s , M., and M. J . Goss.
Composition o f th e le a v e s and s ta lk s o f b a rley a t su c c e ssiv e
sta g e s o f growth, w ith s p e c ia l referen ce to the form ation o f
l i g n i n . J . Agr. R esearch, 51:301-319, 1935.

149.

P h i l l i p s , M., M. J. G oss, B. L. Davis and H. S tev en s.
Composition o f the variou s p a r ts o f the o at p la n t a t su c c e ssiv e
s ta g e s o f growth, w ith s p e c ia l referen ce to the form ation o f
l ig n i n . J. Agr. Research, 59:319-366, 1939.

150.

P h i l l i p s , M., H. Weihe, D. B. Jones and F. A. Csonka.
The dem ethoxylation o f l i y i i n in "the animal body.
E x p tl. B io l. Med., 26:320-321, 1929.

151.

P h i l l i p s , T. G. and M. E. L oughlin.
Composition and d ig e s t ib le energy o f hays fed to c a t t l e .
R esearch, 78:389-395, 1949.

152.

Rathnow, H. D.
Uber das V erhalten des E isen s Nahrung Wahrend der Pansenverdauung
des S oh afes. Inaug. D i s s ., Munich, 1938.

Proc* Soc.

J . Agr.

80

153*

R eid , J. T*
E valuation o f roughages by chem ical and b io lo g ic a l means.
Proo. C ornell N u tr itio n C on f., 57-68, 1950.

154.

R eid, J . T.
P erson al Commmieation. 1952.

155.

R eid, «J. T ., p . G. W bolfolk, w* A. Hardison, C. M. M artin, A. L.
Brundage and H. W. Kaufmann.
A procedure fo r measuring the d i g e s t i b i l i t y o f p asture grass
under grazing c o n d itio n s. J. Dairy S o i . , 34*494, 1951.

156.

R eid , J . T ., P . G. W oolfolk, W. A. H ardison, C. M. M artin, A. L.
Brundage and R. W. Kaufmann.
A procedure fo r measuring th e d i g e s t i b i l i t y o f pasture forage
under grazing c o n d itio n s. J . N u tr itio n , 46:255-269, 1952.

157.

R eid, J. T ., p . J . W oolfolk, C. R» Richards, J . K. L o o s li, K. L.
Turk, J . I . M ille r and R. E. B la ser.
A new in d ic a to r method for the determ ination o f d i g e s t i b i l i t y
and consumption o f forages by ruminants. J. Animal S c i . , 8:
636, 1949.

158.

R eid, J. T ., P.
g* W oolfolk, C. R. Richards, R. W. Kaufmann, J. K.
L o o s li, K. L. Turk, J. I . M ille r and R. E. B la ser.
A new in d ic a to r method fo r the determ ination o f d i g e s t i b i l i t y
and consumption o f forages by ruminants. J. Dairy S o i . , 33*
6 0 -71, 1950.

159.

R it t e r , G. J*
Chemistry o f wood. V II. R ela tio n between methoxyl and lig n in
in wood. md. Eng. Chem., 15*1264-1266, 1923.

160.

Salmon, S . C ., C. 0 . Swanson and C. W. MeCampbe 11.
Experiments r e la tin g to the time o f c u ttin g a l f a l f a .
Agr. Expt. S ta . Tech. B u ll. 15, 1925.

161.

Schneider, B. H.
Feeds o f th e Wbrld, t h e ir D i g e s t i b i li t y and Composition.
Morgantown, W. v a . , W. \Ta* Agr. Expt. s t a . , 1947.

162.

S chneider, B. H. and H* B. E llenber ger*
Apparent d i g e s t i b i l i t y as a ffe c te d by len g th o f t r i a l and by
c e r ta in v a r ia tio n s in the r a tio n . Vt* Agr. Expt. S ta . B u ll.
270, 1927.

163.

Schneider, B. H ., and H. L* Lucas.
The magnitude o f c e r ta in sources o f v a r ia b ilit y in d i g e s t i b i l i t y
d a ta . J . Animal S o i* , 9:504-512, 1950.

164.

S ch n eid er, B. H*, H. L. Lucas, Mary Ann C ip o llo n i, and H elen M.
P a v lech .
The p r e d ic tio n o f d i g e s t i b i l i t y fo r which th ere are on ly prox­
imate com position d ata. J . Animal S c i . , 11:7 7 -8 3 , 1952.

Kans.

61*

165 *

S ch n eid er, B* H ., H. L. Lucas, Helen M. Pavlech and Mary A. C ip o llo n i.
The va lu e o f average d i g e s t i b i l i t y d ata. J . Animal S o i . , 9 :373379, 1950.
9

166*

Sch n eid er, B. H ., H. L. Lucas, Helen M. Pavlech and Mary A. C ip o llo n i.
E stim ation o f th e d i g e s t i b i l i t y o f fee d s from th e ir proximate
com p osition , j . Animal S c i . , 10:706-713, 1951.

167*

Schurch. A* F», L. E. Lloyd and E. W. Crampton.
The use o f chromic oxide as an index fo r determ ining the d ig e s t ­
i b i l i t y o f a d i e t . J. N u tr itio n , 41:629-636, 1950.

168,

Skulmowski, J . , A. Szymanski and T. W yszinski.
P ra k tisch Anwendung e in e r neuen, der sogenannten nq u a lita tiv e n "
oder Indikator-M ethode zur Bestimmung der V erd au lich k eit des
P u tte r s. Ber. Landw. Forschung sa n st. des General-gouvemement s .
1*76-104, 1943.

169*

Snedecor, G. W.
S t a t i s t i c a l Methods.

itiTEanrm’s:--------

The Iowa S ta te C ollege P r e ss, Ames.Iowa.

170.

S o to la , J.
R e la tio n o f m aturity to the n u t r it iv e value o f f i r s t , second and
th ir d c u ttin g s o f ir r ig a te d a l f a l f a . J. Agr. Research, 35*361383, 1927.

171.

S o to la , J.
The chem ical compo s it io n and n u tr itiv e value o f c e r ea l hays as
a ffe c te d t y p la n t m atu rity. J. Agr. R esearch, 54*399-415, 1937.

172.

S o to la , J.
The chem ical com position and apparent d i g e s t i b i l i t y o f n u tr ie n ts
i n c r e ste d wheat grass h arvested in th ree sta g es o f m atu rity.
J . Agr. R esearch, 61*303-311, 1940.

173.

S o to la , J.
The chem ical com position and apparent d i g e s t i b i l i t y o f n u tr ie n ts
in smooth brome grass harvested in th ree sta g e s o f m atu rity. J.
Agr. R esearch, 65*427-432, 1941.

174.

S ta p le s , G. E ., and W. E. Dinusson.
A comparison o f th e r e la t iv e accuracy between seven-day and
ten -d a y c o lle c t io n p eriod s in d ig e s tio n t r i a l s . J . Animal S c i . ,
10*244-250, 1951.

176.

S teen sb erg , V. and J. E. Winther.
D i g e s t i b i l i t y t r i a l s w ith lu c e r n e , and m eal o f f r e s h lucerne and
hay. (Trans, t i t l e ) . F ors^gslab. K^benhavn Beretn. No. 250*1121, 1950. Seen in a b str a c t o n ly . N u tr itio n A b stracts & R e v s.,
21*208, 1951.

176 .

Swanson, E. W., and H. A. Herman*
The d i g e s t i b i l i t y o f Korean lesp ed eza hay and ground Korean
lesp e d e za seed for dairy h e i f e r s . J . Dairy S o i ., 27*263-268,
1944.

82.

177.

S w i f t , R. W* , R . L. Cowan, G. P . B a r r o n , K. H. Maddy and E . C. G r o se .
The e f f e c t o f a l f a l f a a sh upon ro u g h a g e d i g e s t io n i n s h e e p .
J . A nim al S o i . , 1 0 { 4 3 4 - 4 3 8 , 1 9 5 1 .

178.

S w ift, R. W., E. J. Thacker, A. B lack, J . W. B ra tsler and W. H. James.
D i g e s t i b i l i t y o f r a tio n s for ruminants as a ffe e te d by p rop ortion
o f n u tr ie n t s . J. Animal S c i . , 6{432-444, 1947.

179.

Thomas, B ., and D. G. Armstrong.
A study o f some methods a t p resen t used fo r the determ ination
o f l ig n i n . J . Agr. S o i . , 39:335-346, 1949.

180.

Underwood, E. J . , and R. J . Moir.
Cereal hay production in Yfeste r n A u str a lia . I I . The in flu e n c e o f
time o f c u ttin g on the chem ical com position and d i g e s t i b i l i t y o f
wheat and o a ts hay. J . Dept. W. A u str a lia , 21:41-51, 1944.

181.

V irtan en , A. I .
C ited by crampton, E* W. and L. E. Lloyd.
319-327, 1951.

J. N u tr itio n , 45:

182.

Watson, C. J . , J . A. Campbell, W. M. Davidson, C. H. Robinson and
G. W. Muir.
D i g e s t i b i l i t y s tu d ie s w ith ruminanbs. V III. A sso c ia tiv e d i­
g e s t i b i l i t y o f hay and g ra in s. S o i. Agr*, 22:250- 270, 1941.

183.

Watson, C. J . , J . A. Campbell, W. M. David sen, C. H. Robinson and
G. W. Muir.
D i g e s t i b i li t y s tu d ie s w ith ruminants. IX. A sso c ia tiv e d ig e s t ­
i b i l i t y o f g r a in s; wheat bran, gluten fe e d , and soybean o i l m eal.
S o i. A g r ., 22:561-570, 1942.

184.

Watson, C. J . , W. M. Davidson, J. C. Woodward, C. H. Robinson and
G. W. Muir.
D i g e s t i b i l i t y s tu d ie s w ith ruminants. V. A sso c ia tiv e d ig e s t ­
i b i l i t y among roughages and succulent fe e d s . S c i. A g r ., 20:
175-192, 1939.

185.

Watson, C. J . , J. A. Campbell, W. M. Davidson, C. H. Robinson and
G. W. Muir.
D i g e s t i b i l i t y s tu d ie s w ith ruminants. VI. A sso c ia tiv e d i­
g e s t i b i l i t y @f g r a in s: b a r le y , o a ts and o i l cake. S c i. A g r.,
20:238-253, 1939.

186.

Watson, C. J . , J . W. Kennedy, W. M* Davidson, C. H. Robinson and
G. W. Muir.
D i g e s t i b i l i t y stu d ie s w ith ruminants. X. R e la tiv e a s s o c ia t iv e
e f f e c t s o f th e roughages, tim othy and a l f a l f a , w ith b a r le y . S c i.
A g r ., 27:175-182, 1947.

187.

Woodman, H. E.
The r o le o f c e l lu l o s e in n u t r it io n .

B io l. R e v ., 5:273-295, 1930.

83.

188*

"Wbodman, H. E ., K* E. Evans aid D. B. Norman.
N u tr itiv e value o f lucerne. I . Prelim inary stu d ie s o f y i e l d ,
com p osition , and n u t r it iv e v a lu e . J . Agr. S c i . , 23:419-448, 1933.

189.

Woodman, H. E ., R. E. Evans and D. B. Norman.
N u tr itiv e value o f lu o era e. I I . In v e s tig a tio n s in to the in flu e n c e
o f system atic c u ttin g a t th ree sta g e s o f growth on the y i e l d ,
com position and n u t r itiv e value o f lu c e r n e . J . Agr. S c i . , 24:
283-311, 1934.

190.

Woodman, H. E ., and J. Stew art.
The mechanism o f o e llu lo s e d ig e s tio n in the ruminant organism .
I I . She transform ation o f c e llu lo s e in to glu cose by th e agency
o f c e l l u l e s e - s p l i t t i n g b a c te r ia . J . Agr. S c i* , 18:713-723, 1928.

191.

Ufoodman, H. E. and J . Stew art.
The mechanism o f c e llu lo s e d ig e s tio n in the ruminant organism.
I I I . The a c tio n o f c e llu lo s e s p l it t i n g b a c ter ia on the fib r e
o f c e r ta in ty p ic a l feedin g s t u f f s . «T. Agr. S c i . , 22:527-547,
1932.

T A B L E S

85

Table 12.

Average D a ily Dry Matter Consumed and Excreted by Cows Fed
Four Stages o f Orchard Grass Hay.

:
bry Matter Consumed
s
Grain
T otal
_* . Hay
gQLS.
gnis.
gms.

i
s
s

Dry
Matter
Excreted
gras.

Hay Fed

Animal

Stage 1

X65
2408
N635

s 10,052
8 10,454
8
6,433

1,981
3,557
2,786

12,033 8
14,011 s
9,219 s

3,433
3,782
2,326

Stage 2

X65
2408
H635

8 10,315
8 10,727
8
6,601

1,981
3,557
2,786

12,296 3
14,284 3
9,387 s

3,471
3,668
2,318

Stage 5

X65
2408
N635

8 10,241
1 10,651
8
6,554

1,981
3,557
2,786

12,222 s
14,208 s
9,340 8

4,117
4,348
2,649

Stage 4

X54
2408
3J635

8
7,290
: 10,530
8
6,480

2,496
3,557
2,786

9,786 s
14,087 8
9,266 i

3,316
4,955
3,102

86

T a b le 13*

Com position o f the Dry Matter o f Feeds and F eces used i n D ig e stio n
T r ia ls o f Orohard Grass Hay*

M aterial

P ro te in

F iber

—

IT*F* E*

Ether
E xtract

w ~

Grain 86

Ash
- j r

9*18

2.17

8 1 .1 4

3.63

3.88

Stage 1

24. 78

26.88

35.02

3.99

9 . 53

Stage 2

15*80

28.15

4 5 .8 2

3.46

6 .7 7

Stage 3

13*00

31.77

44. 24

3.91

7.0 8

Stage 4

12*38

35.05

41.16

4 .2 4

7.17

Stage 1
X65
2408
N635

24*86
26.45
26.97

15.60
14.26
14.69

35.72
37.45
35.79

8.09
7.27
7.67

15.73
14.80
14.88

Stage 2
X65
2408
N635

20*19
20.73
19.38

20.25
18.92
18.44

38.18
41.42
41.74

7.65
6.82
7.19

13.73
12.47
13.25

Stage 3
X65
2408
N635

15.96
1 6 .8 4
15*46

24.47
22.69
22.93

39.27
41.11
41.74

7 .8 4
7 .1 8
7 .5 3

12.46
12.18
12. 34

Stage 4
X54
2408
N635

1 2 .6 4
1 4 .3 4
14.50

24.76
23.76
24.22

41.88
43.88
43.84

7 .4 3
7 .0 6
7.09

1 1 .1 4
10.96
11.55

Orchard Grass

Feoes

87

T a b le 14*

Apparent D ig e stio n C o e ffic ie n ts o f th e R ation C onstituents by
Cows Fed. Four Stages o f Orchard Grass Hay

Dry
Matter

P ro tein

Fiber

N .F.E.

Ether
Extraci

Stage 1
2408
H635

71 .5
73.0
74.8

68.1
66.0
66.1

8 0 .5
8 1 .3
80.9

76.1
7 8 .4
8 1 .6

4 1 .2
49.8
50.0

Average

73.1

66.7

80.9

78.7

47.0

Stage 2
X65
2408
H635

71.8
7 4 .3
7 5 .3

61.3
63.1
6 5 .4

7 6 .2
77.7
77.7

79.1
8 0 .4
8 1.8

38.0
51.1
4 8 .4

Average

7 3.8

63.3

7 7 .2

8 0 .4

4 5 .8

Stage 3
.......X5F
2408
H635

6 6 .3
6 9 .4
7 1 .6

56.5
57.0
63.0

69.5
71.5
7 1 .7

7 3 .7
76.5
78.6

31.6
43.0
44 .1

Average

6 9 .1

58.8

70.9

7 6 .3

3 9 .6

Stage 4
.......XB*
2408
N635

6 6.1
64.8
66.5

59.8
56.2
6 0 .6

67.5
68.8
6 7 .6

72.1
69.9
7 2 .4

3 5 .7
3 9 .4
4 1 .4

Average

6 5.8

58.9

6 8 .0

7 1 .5

38.8

88

T a b le 15

Apparent D ig e stio n C o e ffic ie n ts o f the C on stitu en ts o f Orchard
Grass Hay* out a t Pour S tages o f M aturity
Dry
M atter

P ro te in

F iber

N .F.E.

X65
2408
H635

68*6
68*6
69.9

67*6
64*8
64*6

81*5
83*0
8 3 .0

6 9 .3
6 8 .4
7 0 .3

33.1
38 .2
55*6

Average

69.0

65.7

82.5

69*3

35.6

Stage 2
X65
2408
H635

69.1
7 1 .4
70.8

59*8
59*1
63 .1

77.0
79.1
79.6

75.0
7 4 .4
7 4 .7

28.2
37.2
32.7

Average

7 0 .4

60.7

78.6

74.7

32.7

Stage 5
X65
2408
N635

6 2.5
63.8
65.5

54.0
52.8
59.3

7 0 .1
7 2 .7
7 3 .2

67.5
6 7 .6
68.9

21.7
2 9 .1
27.2

Average

63.9

5 5 .4

72.0

6 8 .0

26.0

4
X54
2408
H635

5 9 .3
57.6
5 8 .2

55.6
51.5
55.9

68.5
69.8
69.0

59 .3
55.9
5 6 .6

2 0 .1
25.5
24.7

Average

5 8 .4

54.3

69.1

57.3

2 3 .4

Ether
E xtra ct

Stage 1

Stage

♦ D ig e stio n c o e f f i c i e n t s o f Orchard Grass Hay c a lc u la te d ”^y d iff e r e n c e ”
u s in g th e d ig e s t io n c o e f f i c i e n t s o f c o m reported by Schneider (1 9 4 7 ).

89

T a b le 16

Composition o f th e Dry Matter o f Feeds and Feces used for C a lcu la tin g
D ig e stio n C o e f fic ie n ts by the R atio Technique on T otal C o lle c tio n Samples

M aterial

L ignin Content
* Crude
Corrected :
Lignin
s
1 Lignin
%

Grain 86
X65
2408
N.635
X54
Orchard Grass
Stage 1
Stage 2
Stage 3
Stage 4

.518
.518
.518
.623

Chromium
Oxide

%

.505
.505
.505
.607

.7341
• 4318
.5620
.5200

P lan t
Pigment
u n its/g n u
5.41
5.41
5.41
7 .6 3
901.3
595.3
562.1
484.0

7.7 7
6.74
7.97
9 .5 6

5.71
5 .1 2
6.32
8 .1 2

21.61
20.63

14.77
13.69
13.74

.4367
• 4246
.6667

2634.0
2203.3
2414.2

Stage 2
X65
2408
$635

19.04
16.99
17.63

13.23
12.11
12.71

.4320
.4362
.6315

1779.0
1742.5
1897.1

Stage 5
X65
2408
$635

19 .3 2
1 7 .3 6
18.12

1 4 .5 2
13.18
13.36

.3352
.3356
.5262

1268.9
1274.7
1395.0

18 .8 3
17.88
1 8 .6 4

15.09
14.72
15.25

.3974
.3157
.4852

963.5
994.7
997.0

F eces
Stage 1
X65
2408
N655

Stage 4
X54
2408
$655

2 0 .2 0

90

T a b le 17*
C o m p o s itio n © f t h e P r y M a tte r o f F e c e s u s e d f o r C a lc u la t i o n o f D i g e s t i o n
C o e f f i c i e n t s b y t h e R a t io T ech n iq u e o n P a r t i a l C o l l e c t i o n S a m p les

Stage
and
Animal
Stage 1
X65
2408
N635

Stage 2
X65
2408
N635

Stage 3
X65
2408
N635

Stage 4
X54
2408
H6o5

Ether
E xtract
%

P la n t
Chromium
Pigment
Oxide
%
u n it s /m .

Day

P r o te in
%

F iber
%

H .F.E.
%

1
2
3
1
2
3
1
2
3

22.65
23.78
24.31
22.91
22.60
22.84
24.31
25.54
23# 84

15.31
14.41
15.60
14.48
14.23
13.77
13.64
12.52
13.02

40.24
39.05
37. 64
42.30
44.29
43.31
41.66
41 .5 2
39.85

7 .7 3
8 .0 2
8 .0 6
6 .7 4
6 .5 4
7.28
6.71
6 .8 6
8.29

.4634
.4353
• 4459
• 4541
.4231
• 4299
.6672
.6340
• 6692

2370.6
2494.6
2433.1
2049.9
1983.3
2192.1
2167.6
2147.6
2239.0

1
2
3
1
2
3
1
2
3

1 7 .2 4
17.65
17.87
20.34
17.56
17.57
19.46
18.35
17.45

20.66
20.22
20.35
1 8.92
1 9.02
1 8 .7 4
17.35
18.12
18.15

41.78
41.77
41.71
4 1.52
45.34
45.40
42.43
44.27
44.43

7.63
7.55
7.69
6.75
7.08
7.00
7.75
7.16
7.55

• 4555
• 4586
• 4289
.4527
.4716
.4713
.6979
.6820
.6875

2080.5
2005.8
2058.6
1881.2
1816.4
1788.6
2127.1
1939.5
1884.5

1
2
3
1
2
3
1
2
3

14.80
14.98
1 4 .9 1
16.08
1 5.13
1 4.56
1 6.02
1 3.71
15.70

25.70
24.36
23.32
22.70
2 3.91
23.18
21.49
24.00
21.25

39.91
40.81
41.54
40.43
41.15
42.79
43.13
42.94
43.71

7.90
8.11
8.31
8 .5 4
8.08
7.77
7.65
7 .9 2
7 .9 2

.3560
.3735
.3768
.3803
.3470
.3511
.5745
.5749
.5878

1460.0
1486.2
1532.2
1405.7
1363.3
1379.5
1292.2
1388.4
1450.7

1
2
3
1
2
3
1
2
3

12.46
1 2.31
1 2 .7 4
12.85
13.00
13.66
13.23
1 2 .4 2
1 3.46

24.21
24.40
23.59
24. 29
23.99
24. 24
23.70
24. 21
23.64

44.26
44.72
44.40
46.57
46.10
44.54
45.44
45.64
44.65

7.00
7 .1 6
7 .3 3
6.87
6.91
7.41
7 .14
7.30
7 .23

•4193
.4400
.4264
.3271
.3320
.3259
.5000
.4714
• 4883

-—

—
—
—

—
—
- -

—

91

T a b le 18*
D i g e s t io n C o e f f i c i e n t s C a lc u la t e d b y t h e R a t io T ech n iq u e on t h e
T o t a l C o l l e c t i o n S am p les

Method
Chromium

Pigm ents

Crude
L ignln

Animal

Ether

Dry
P r o te in

Fiber

Stage 1

X65
2408
R635

72*3
7 4 .2
7 4 .6

7 3 .6
6 7 .4
65.8

81.1
82.1
80.7

74.4
79.3
8 1 .4

4 3 .0
5 1 .3
4 9 .6

Stage 2

X65
2408
N635

7 2 .6
7 6 .6
74.8

62.5
66.6
64.9

76.9
80.0
77.6

7 9 .7
8 2 .0
8 1 .2

39.8
5 5 .7
4 7 .2

Stage 3

X65
2408
N635

6 4 .5
67.9
6 8 .2

5 4 .3
54.9
5 8 .5

67.8
70.1
68.2

72.2
7 5 .4
76.0

27.9
4 0 .2
37 .3

Stage 4

X54
2408
N635

66.6
65.7
65.3

64.3
57.3
59.2

68.9
69.6
66.6

71.1
70.7
7 1 .4

3 6 .6
4 1 .0
3 9 .3

Stage 1

X65
2408
R635

7 1 .4
69.7
73.9

72.7
61.8
64.9

80 .4
79.1
80.2

73.5
75.8
80.9

4 1 .1
4 3 .0
4 8 .2

Stage 2

X65
2408
N635

71.9
74.3
77.8

61.5
63.2
69.2

7 6 .2
78.0
8 0 .4

7 9 .1
8 0 .2
8 3 .5

3 8 .2
5 1 .2
5 3 ,6

Stage 3

X65
2408
N635

62.8
66.8
7 1.6

52.1
5 3 .4
63.0

66.3
69.1
71.6

71.9
7 4 .6
7 8 .6

24.5
3 8 .2
4 4 .0

St«ge 4

X54
2408
H635

62.5
6 3 .5
6 5 .2

59.9
5 4.5
59.0

65.0
67.6
66.5

67.5
68.8
7 1 .3

28.7
37.1
39.1

1

X65
2408
N635

69.6
7 0 .6
73.0

72.0
63.0
63.6

79.2
79.7.
79.5

71.9
76.5
8 0 .2

3 7 .4
4 4 .7
4 6 .4

2

X65
2408
N635

69.9
70.1
72.8

58.7
57.0
61.5

74.5
74.0
75.5

77.6
77.2
8 0 .1

3 3.7
4 3 .3
4 3 .1

3

X65
2408
N635

6 5 .0
6 5 .3
68.7

54.9
51.2
59.2

68.3
67.7
68.8

72.6
7 3 .4
7 6 .4

28.9
3 5 .2
3 8 .4

4

X54
2408
N635

60.7
58.8
6 3 .4

58.0
4 8 .6
57.0

63.3
65.4
64.8

65.9
64.8
69.9

25.2
29.0
36.0

92

T a b le 18*

Method
Corrected
Id g a in

C o n tin u e d

Jftnimal

Dry
Matter

P ro te in

Fiber

Stage 1

X65
2408
N635

67*2
68.0
69.9

6 8 .7
59.6
5 9 .6

7 7 .6
77.8
77.2

69.6
74.3
78.0

3 2 .4
39.7
4 0 .0

Stage 2

X65
2408
N635

67.7
6 8.0
7 1 .2

55.8
54.0
59.2

7 2.7
7 2 .2
7 4.0

76.1
75.6
78.8

29.0
39.3
39.7

Stage 3

X65
2408
N635

63.6
63.7
66.2

53.2
4 9 .0
55.9

6 7 .0
66.2
66.3

71.5
7 2 .2
74.5

26.0
32.3
33.5

Stage 4

X54
2408
N635

58.9
58.6
63.1

5 6.1
4 8 .4
56.5

6 1 .7
6 3 .2
6 4 .4

6 4 .4
64.6
69.5

21.9
28.3
35.3

Hay

E .F .E .

Ether
E x tra ct

93

T ab le 1 9 .
D i g e s t i o n C o e f f i c i e n t s C a lc u la t e d b y t h e Chromium R a t io
T e c h n iq u e o n t h e P a r t i a l C o l l e c t i o n S am p les

Hay______ Animal
Stage 1

X65
2408
N635

Stage 2

X65
2408
N635

Stage 3

X65
2408
N635

Stage 4

X54
2408
N635

C o lle c tio n
Dry
Day_______ Matter

P ro tein

Fiber

N.F.E.

Ether
E xtract

1
2
3
1
2
3
1
2
3

73*9
72.2
72.9
75.8
74.1
7 4 .5
7 4 .6
7 3 .3
7 4 .7

7 3 .4
7 0.3
7 0.3
7 3 .4
71.8
72.0
69.2
6 6 .0
60.9

8 2 .5
8 2 .5
8 1 .5
73.0
8 2 .1
8 3.0
80.8
82.8
83.0

7 5.3
74.5
7 6.0
78.1
7 5 .4
7 6 .4
8 1 .4
7 7 .3
79.6

4 8 .7
43.3
4 4 .4
57.8
56.1
51.9
49.6
53.6
4 7 .0

1
2
3
1
2
3
1
2
3

74.0
73.0
72.4
76.3
77.2
7 7 .2
76.1
75.5
75.7

69.6
67.7
66.6
72.3
71.6
71.7
66.4
67.6
69.4

77.6
7 7 .2
76.6
7 9 .4
80.0
8 0 .3
79.7
78.3
78.4

78.9
78.1
77.6
79.9
81.1
81.1
82.0
80.8
80.8

4 3 .1
4 1 .5
39.1
51.8
54.1
54.7
4 7 .0
49.9
4 7 .7

68.2
71.2
72.7
73.5
69.5
70.7
72.7
69.5
73.6

7 3 .4
74.1
73.9
78.5
76.0
75.7
77.2
7 7 .4
77.5

31 .6
33.1
32.0
37.0
34.6
37.9
4 1 .5
39.6
40.9

71.2
72.3
7 2 .4
69.8
70.6
69.9
68.1
65.4
67.4

72.5
73.5
72.8
69.9
7 0 .6
7 1.0
7 1 .1
69.2
70.9

4 3 .4
4 4 .8
4 1 .7
4 4 .2
4 4 .7
39.6
4 0 .3
3 5 .2
3 8 .1

1

6 6 .6

2

6 8 .1

3
1
2
3
1
2
3

6 8 .4
7 1 .6
68.9
69.2
70.8
70.9
7 1 .5

60.1
61.5
62.0
62.0
60.8
62.7
60.7
61.5
62.4

1
2
3
1
2
3
1
2
3

6 8 .4
69.9
68.9
6 6 .7
6 7 .2
66.6
66.1
64.1
65.3

66.7
68.6
66.5
62.9
63.0
60.4
60.9
61.0
59.2

94

T a b le 20
D i g e s t i o n C o e f f i c i e n t s C a lc u la t e d b y t h e P ig m en t R a t io T ech n iq u e
o n t h e P a r t i a l C o l l e c t i o n S a m p les

S*X_
Stage 1

Animal
X65
2408
N635

Stage 2

X65
2408
N635

X65
2408
N635

C o lle c tio n
Day

Dry
Matter

P ro tein

Fiber

N. F.E.

Ether
E x tra ct

1
2
3
1
2
3
1
2
3

6 8 .2
69*8
69*0
67.1
66.0
69.3
70.9
7 0 .6
71.8

67.6
67.7
66.1
63.8
63.1
66 .2
64.8
62.7
66.6

78.7
80.9
78.8
76.9
76.6
77.5
78.0
81.1
81.1

69.9
7 2 .3
7 2 .6
70.3
67.8
71.5
78.8
75.1
7 7 .4

37.5
3 8 .3
3 6 .5
4 2 .6
4 2 .4
4 2 .0
4 2 .3
4 9 .1
4 1 .2

1
2
3
1
2
3
1
2
3

76.0
75.1
7 5 .7
76.2
75.3
74.9
8 0 .2
7 8 .3
7 7 .7

71.9
70.1
70.5
72.2
69.3
68.9
72.3
71.3
71.9

79.3
79.0
79.4
79.3
78.4
78.3
83.2
80.8
80 .2

8 0 .5
79.8
8 0 .3
79.8
7 9 .5
79.2
85.1
83.0
8 2 .4

4 7 .3
4 5 .9
4 6 .4
5 1 .6
5 0 .3
50.2
5 6 .3
55.7
5 2 .0

1
2
3
1
2
3
1
2
3

67.7
68.3
69.2
69.9
69.0
69.4
69.4
71.5
72.7

61.4
6 1 .6
63.0
59.8
61.0
62.9
58.7
67.1
63.6

69.2
71 .3
7 3 .4
72.0
69 .6
70.9
7 1 .3
70.2
74.7

74.3
74.2
74.5
7 7 .3
7 6 .2
75.5
76.1
78.0
7 8 .4

33.9
33.3
33.7
33.7
34.9
38.2
3 8 .6
40.9
43 .5

Stage 4^*^

(1 )

S u ita b le samples tore not a v a ila b le fo r determ ination o f the p la n t
pi©nent co n cen tra tio n o f the fe c e s for a l l anim als used in the t r i a l
w ith Stage 4 Orchard Grass hay*

95

T a b le 21

Comparison o f D ig e stio n C o e ffic ie n ts C alculated by sev era l
methods on Four Stages o f Orchard Grass Hay p lu s Grain

3

3

C o n stitu e n t: Standard:

Chromium: t ig n in k atio
: P i gment: Chromium :Pigm ent
Ratio : Crude : Corrected t Ratio : Ratio i Ratio

Stage 1
Dry Matter
P r o te in
F iber
N* F.E,
Ether Ext*

73
67
81
79
47

74
69
81
78
48

71
66
80
76
43

68
63
78
74
38

72
67
80
77
44

74
70
81
77
50

69
65
79
73
41

Stage 2
Dry M atter
P ro tein
F ib er
N.F*E.
Ether Ext*

74
63
77
80
46

75
65
78
81
48

71
59
75
78
40

69
56
73
77
36

75
65
78
81
48

75
69
79
80
48

77
71
80
81
51

Stage 3
Dry M atter
P ro te in
F iber
N*F.E.
Ether Ext*

69
59
71
76
40

67
56
69
75
35

66
55
68
74
34

65
53
67
73
31

67
56
69
75
36

70
62
71
76
36

70
62
71
76
37

Stage 4
t r y Matter
P ro te in
F iber
U*F*E*
E ther Ext*

66
59
68
72
39

66
60
68
71
39

61
55
64
67
30

60
54
63
66
29

64
58
66
69
35

67
63
70
71
41

-—
—
—
——

PART I I

STUDIES ON THE COMPOSITION OF LIGNIN ISOLATED FROM ORCHARD
GRASS HAY CUT AT FOUR STAGES OF MATURITY AND FROM THE CORRES­
PONDING FECES

INTRODUCTION

L ignin has been reported to be in d ig e s t ib le by a number o f workers
( 7 , 9 , 1 3 , 1 4 , 1 6 , 17, 19, 3 8 ).

Other rep o rts in d ic a te th a t varying amounts

o f l ig n i n may be d ig e ste d or broken down in the ruminant d ig e s t iv e t r a c t
( 4 , 8 , 10, 11, 18, 21, 22, 2 7 ).
Sin ce th e chem ical stru ctu re o f lig n in has n ot been e s ta b lis h e d i t i s
n o t f e a s ib le to i s o l a t e or determine a product o f uniform com position from
d if f e r e n t m a te r ia ls .

C ertain c h a r a c t e r is t ic s o f crude lig n in prep aration s

v ary c o n sid era b ly depending upon the m a teria l from which i t i s is o la t e d and
th e method used fo r i t s i s o l a t io n .

E xten sive s tu d ie s have been made o f -the

c h a r a c t e r is t ic s o f lig n in is o la t e d from variou s woods but on ly lim ite d
s tu d ie s have been reported on lig n in prepared from forage p la n ts important
in animal fe e d in g .
P h illip s e t a l . (33) found 4 .3 4 p ercen t n itr o g en in th e lig n in ob­
ta in e d from o a t p la n ts 7 days old which decreased to 1.26 p ercen t n itro g en
in th e lig n in from p la n ts 84 days o ld .

Bondi and Meyer (4) reported from

1 .1 8 to 1 .6 3 p ercen t n itro g en in th e lig n in from four grass s p e c ie s and
from 2 .9 2 to 3 .3 6 percent n itr o g e n in th e lig n in from four legum es.

The

lig n in is o la t e d from th e corresponding f e c e s a l l had s l i g h t l y h igh er n it r o ­
gen c o n te n ts.

They a lso showed th a t the lig n in n itr o g en was r e s is t a n t to

h y d r o ly s is by strong a cid (5 N s u lfu r ic a c id ) and weak acid ( 0 .5 N hydro­
c h lo r ic a c id ) and by p ep sin added to the weak a c id .

These r e s u lt s led them

to conclude th a t th e n itro g en in crude lig n in p rep aration s was n o t p resen t
a s p r o te in n itr o g e n .

Furthermore, th e d ig e s tiv e enzymes o f the ruminant

did n ot reduce th e n itr o g en con ten t o f th e lig n in .

98

Norman and Jenkins (25) b eliev ed th a t p r o te in degradation products
fo llo w in g th e treatm en t o f p la n t m aterial vdth strong acid r e s u lte d in high
l ig n i n y i e l d s ra th er than p r o te in per se*

paloheimo ( 2 6 ) , Wfcksman and

S tev en s ( 4 0 ) , P h i l l i p s ( 2 8 ) , and DeMan and DeHeus (1 2 ) have co rrected crude
l ig n i n v a lu e s by deducting the n itrogen content m u ltip lie d by th e fa c to r
6*25*

P h i ll i p s (2 9 ) la t e r f e l t th a t because th ere was n o t a con stan t re­

la t io n between the amount o f p r o tein added to samples fo r th e determ ination
o f lig n in and th e s iz e o f th e error in volved th a t the apparent lig n in v a lu es
should n ot be co rrected but the percent o f nitrogen in th e lig n in should be
reported*
Thomas and Armstrong (3 9 ) found amino a cid s in th e hydro ly s a t e s from
crude lig n in and proposed th a t the fa c to r 6*25 fo r con vertin g lig n in n it r o ­
gen to p r o te in was valid *

DeMan and DeHeus (12) found th e ty r o sin e and th e

tryptophane n itr o g e n in the lig n in is o la t e d from Lolium perenne was in
agreement w ith th a t fo r th e tru e p r o te in o f the grass*

The tryptophane

n itr o g en was determ ined on lig n in is o la t e d w ithout the use o f concentrated
s u lfu r ic acid*
Bondi and Meyer (4 ) found about 5 percent methoxyl in the lig n in ob­
ta in e d from legumes and about 10 percent methoxyl in the lig n in is o la te d
from v a rio u s g r a s s e s .

They a lso found v ery l i t t l e d iffe r e n c e in the methoxyl

con ten t o f the l i g n i n is o la t e d from the corresponding f e c e s which would in ­
d ic a te th a t th e re i s very l i t t l e breakdown o f th e eth er lin k a g es in the
l ig n i n m olecule during passage through the d ig e s tiv e tra c t*

O xidation o f

th e l ig n i n from v a rio u s p la n ts gave y ie ld s o f from 4*2 to 21.6 p ercen t
aldehydes w h ile o x id a tio n o f th e fe c a l l i gains gave n e g lig ib le q u a n titie s
©f a ld eh y d es, in d ic a tin g a change in th e sid e chains attached to the lig n in
m olecule during passage through th e i n t e s t in a l t r a c t .

The lig n in from the

99

g r a sse s gave a much higher percentage o f aldehydes fo llo w in g o x id a tio n than
th e legumes but th e r a tio o f v a n i l l i n to p-hydroxy-benzaldehyde was approx­
im a tely 2 to 1 in a l l c a s e s .
S to n e, B lu n d ell and Tenner (37) found th a t the r a tio s o f v a n i l l i n to
syrin ge aldehyde d id n o t remain constant in th e wheat p la n t a t d if f e r e n t
sta g e s o f growth sin ce the percentage o f syringealdehyde was lower than
v a n i l l i n in th e young p la n ts and higher in th e more mature p la n t s .

Con­

cu rren t in c r e a se s in the methoxyl content o f the lig n in were observed.
Csonka, P h i ll i p s and Jones (10) and P h illip s e t a l . (34) reported a
lo s s o f 36.7 p ercen t o f the methoxyl groups a sso c ia te d w ith the lig n in in
a r a tio n o f hay, g ra in and s ila g e fed to a cow.

F ran cois, Leroy and Levy

(15) rep orted th a t 50 percent o f the methoxyl content o f th e lig n in d i s ­
appeared in th e d ig e s tiv e t r a c t o f ruminants fed a l f a l f a hay alon e and in
com bination w ith w heat, and d ried b eet pulp*

The apparent d i g e s t i b i l i t y

o f th e lig n in o f a l f a l f a was approxim ately 8 p ercen t.
Pazur and DeLong (27) P h illip s e t a l . (34) and Csonka, P h illip s and
Jones (1 0 ) have reported in creased urinary e x cr etio n o f hippuric a c id when
in crea sed amounts o f lig n in are fed and f e l t th a t t h i s in d ica ted a metab­
o lism o f lig n in in th e animal body.

R ogozinski and Starzewska (3 6 ) f e l t

th a t l ig n i n was in d ig e s t ib le by sheep and played no p art in the form ation
o f h ip p u ric a c id .
T his study was conducted to determine c e r ta in c h a r a c te r is tic s o f the
l ig n i n is o la t e d from orchard grass hay cu t a t four sta g e s o f m aturity and
from th e corresponding fe c e s o f d airy cows fed th e se fo r a g e s.
EXPERIMENTAL PROCEDURE
The method o f conducting th e d ig e s tio n t r i a l s and the c o lle c t io n and
h an d lin g o f th e samples have been p rev io u sly presented (p art l ) .

100

The n itr o g e n c o n ten t o f the lig n in was determined "by the m icrok^eldahl
method o f th e A sso c ia tio n o f O f f ic ia l A g ricu ltu ra l Chemists (3) on samples
o f th e l i g n i n is o la t e d from th e various m a te r ia ls by th e method o f E l l i s ,
Matrone and Maynard (13)*
The t o t a l m ethoxyl groups in the fe e d s fed and the fe c e s voided and
a lso th e m ethoxyl con ten t o f the lig n in is o la t e d from th e se m a ter ia ls were
determ ined by the method o f Clark ( 5 , 6 ).
The b en zoic a c id con cen tration in the u rin e was determined by th e
method o f Kingsbury and Swanson (20)*
RESULTS AND DISCUSSION
The amounts o f lig n in consumed and excreted and the percent recovery
o f l ig n i n in th e fe c e s and the percent o f lig n in d ig e ste d are given in
Table 22.

Sin ce lig n in r e c o v e r ie s were a l l somewhat lower than i s d e sir a b le

f o r a m a teria l to be su ita b le fo r use as an in e r t tr a c e r m aterial i t ex­
p la in s th e tendency fo r the lower d ig e s tio n c o e f f i c i e n t s p r e v io u sly pre­
sen ted (P art I ) th a t were c a lc u la ted by the lig n in r a tio tech n iq u e.

"When

plan ning t h i s experim ent i t was p o stu la ted th a t i f the lig n in o f orchard
grass was p a r t i a ll y d ig e ste d th a t there might be a range in th e d i g e s t i b i l ­
i t y o f lig n in th a t would show higher d i g e s t i b i l i t i e s o f the lig n in in im­
mature orchard grass than in th© more mature s ta g e s .

Since lower d ig e s t ­

i b i l i t y o f the l ig n i n in th e immature orchard grass hay r a tio n was secured
i t seemed d e sir a b le to in v e s tig a te some o f the c h a r a c te r is t ic s o f the lig n in
is o la t e d from the fee d s and f e c e s from th e se d ig e s tio n t r i a l s .

The n itr o g en

co n ten t o f th e lig n in is o la t e d from the four sta g e s o f orchard grass hay
and th e corresponding fe c e s are presen ted in Table 23.

The lig n in is o la t e d

from th e immature orchard grass had a higher n itro g en con ten t (4 .2 5 p ercen t)
than th e lig n in is o la t e d from the most mature orchard grass (2 .4 1 p e r c e n t).
L ign in is o la t e d from the corresponding fe c e s had average n itr o g en con ten ts

101

0 f 5*19 and 2*91 percent r e s p e c tiv e ly .

The p r o te in content o f th e dry

m atter o f th e immature grass was 24*78 percent w h ile the p r o te in con ten t
o f th e most mature orchard grass was 12*38 percent*

The p r o te in con ten t

o f th e corresponding fe c e s averaged 26.09 and 13.83 percent r e s p e c t iv e ly .
Sm all d iffe r e n c e s were obtained between the n itro g en content o f th e lig n in
from each sta g e o f orchard grass hay and th e n itro g en con ten t o f th e lig n in
is o la t e d from th e corresponding fec es*

The ”tru e l i g n i n 11 co n ten ts o f each

sta g e o f hay and the corresponding f e c e s were c a lc u la te d by c o rr ec tin g the
crude l ig n in c o n ten t fo r th e n itro g en content o f th e lig n in m u ltip lie d by
th e fa c to r 6*25*

While th ere i s con sid erab le controversy concerning the

nature o f the n itr o g en p r e sen t in the lig n in p rep a ra tio n s, th e work o f
DeMan and DeHeus (12) and Thomas and Armstrong (39) in d ic a te s th a t th e
use o f a p r o te in fa c to r may be j u s t i f i e d in con vertin g the n itro g en p res­
en t in the l i g n i n t o protein*
The crude l ig n i n co n ten ts o f the four stages o f orchard grass hay o f
in c r e a sin g m aturity were 7*77, 6*74, 7*97, and 9*56 percent r e sp e c tiv e ly *
L ignin i s g e n e r a lly considered as a c o n stitu e n t th a t in c r e a se s w ith ad­
vancing m a tu rity o f th e p la n t ( 2 , 9 , 23, 30, 31, 32, 33, 35, 41)*

Other

work ( 2 , 24) w ith orchard grass has shown th a t the lig n in con ten t i n i t i a l l y
d ecrea ses and th en p r o g r e ss iv e ly in c r e a se s w ith advancing m aturity and
th e se changes are concommitant

w ith p rogressive in c re a se s in the crude

f ib e r co n ten t and p r o g r e ssiv e d ecreases in the crude p r o tein content*
These r e s u l t s are in agreement

w ith those found in t h is in v e stig a tio n *

There i s evid en ce th a t sim ila r

changes occur in tim othy ( 3 1 ) , o a ts ( 3 3 ) ,

p eren n ia l ryegrass ( 2 ) , t a l l fescu e (2 ) and burnet ( 2 ) .

This p a ttern of

change has n o t been observed in a l f a l f a , t r e f o i l and yarrow ( 2 ) .

m o th er

th e se changes are a p h y s io lo g ic a l c h a r a c te r is tic o f the growth o f c e r ta in

102

g r a sse s or whether th e re i s an inh eren t error in the determ ination o f lig n in
in immature g ra sses has n ot been determined.
The tr u e lig n in in ta k e s and e x c r e tio n f o r each stage o f hay fed was
c a lc u la te d and th e se data w ith the r e c o v e r ie s and d i g e s t i b i l i t i e s o f the
tr u e l ig n in are presen ted in Table 24#

The apparent d ig e s tio n c o e f f ic ie n t s

fo r tru e lig n in are h igh er than th ose c a lc u la te d for crude lig n in *

I f th e

r e c o v e r ie s o f th e tru e lig n in were higher than th o se found fo r th e crude
l ig n i n one could assume th a t a h igh er d i g e s t i b i l i t y o f the n itro g en co n ta in ­
in g f r a c t io n o f the crude lig n in had r e su lte d in greater l o s s e s o f t h i s por­
t io n in p a ssin g through the d ig e s tiv e tra ct*

Comparison o f the n itro g en

c o n ten ts o f the l ig a i n is o la t e d from th e various orchard grass hays and
th e corresponding fe e e s (Table 23) does not in d ic a te th a t t h i s occurred*
S in ce o th er stu d ie s (1 0 ,2 7 ,3 4 ) have in d ic a ted th a t degradation pro­
du cts o f lig n in may cause in creased urinary ex cr etio n o f benzoic a c id ,
d eterm in ation s were made o f the benzoic a c id e x c r e tio n by each animal fe d
th e four sta g e s o f orchard grass hay*

Table 25 g iv es the amounts o f crude

l ig n in and tru e l ig n i n fed and d ig e ste d by each animal and the urinary
e x c r e tio n o f benzoic aoid per 100 grams of lig n in fed and d ig e s te d .

The

benzoic a c id e x c r e tio n per u n it of lig n in fed is somewhat lower in th e
mature hay than i n the other th ree sta g e s o f l e s s mature hays*

I f the

amount o f urinary b en zoic acid e x c r e tio n i s in flu en ced la r g e ly by the
degree o f l i ^ i i n degradation th e se fig u r e s would in d ic a te a lower d i­
g e s t i b i l i t y o f lig n in i n the more mature orchard grass hay.

This i s n ot

supported by th e consum ption-excretion fig u r e s fb r crude lig a in given in
Table 22.

I t i s p o s s ib le th a t oth er c o n stitu e n ts o f immature orchard

grass co n trib u te to the form ation and e x c r e tio n o f benzoic a c id .
The m ethoxyl c o n ten ts o f the feed and f e c e s on a dry w eight b a s is
are g iv en in Table 26.

A p r o g r essiv e in crea se in the t o t a l methoxyl

103

c o n ten t o f th e hay occu rs w ith in c r e a sin g m atu rity from 1 ,4 1 p ercen t to
1 .8 5 p ercen t and sim ila r in c r e a se s occur in th e methoxyl con ten t o f the
f e c e s from anim als fe d th ese hays.

The methoxyl con ten t o f the lig n in from

the immature hay i s lower (7*84 p ercen t) than th a t from the other th ree
sta g e s which are sim ila r in methoxyl con ten t (1 0 .6 0 , 10.73 and 10.41 per­
c e n t) .

Comparable changes occur in the methoxyl content o f th e lig n in

is o la t e d from the corresponding fe c e s .

Bondi and Meyer (4) found approx­

im a tely 10 p ercen t methoxyl groups in the lig n in is o la t e d from se v er a l
sp e c ie s o f g r a ss.

Their work a lso in d ic a te s th a t each str u c tu r a l u n it o f

the l ig n i n m olecule from grasses con tain s two methoxyl groups which would
g iv e a t h e o r e t ic a l methoxyl content o f 9 .9 p e rcen t.

P h illip s e t a l . (3 3 )

found the methoxyl content o f the lig n in o f o a ts in creased from around
4 to approxim ately 15 p ercen t during growth to 84 days o f age.

Sim ilar

changes occurred in th e lig n in o f barley p la n ts (32) and tim athy p la n ts
(31) during developm ent.

The percentages o f the t o t a l methoxyl groups

th a t were a ss o c ia te d w ith th e lig n in in th e four sta g es o f orchard grass
hay in c r e a sin g in m aturity were 3 1 .9 , 3 5 .1 , 4 0 .7 and 4 5 .4 p ercen t, re­
s p e c t iv e ly .

Adams and Castagne ( l ) found 8 2 .4 percent and 8 1 .7 percent

o f the t o t a l methoxyl groups o f wheat and o a t straw , r e s p e c t iv e ly , in th e
lig n in f r a c t io n .

P h i l l i p s ani Goss (28) found from 52.0 to 81.1 p ercen t

o f th e t o t a l m ethoxyl groups a sso c ia te d w ith the lig a i n fr a c tio n o f b a rley
p la n ts a t variou s sta g e s o f development.

From 39.3 to 8 5 .7 percent o f the

t o t a l m ethoxyl co n ten t o f th e o a t p la n t was found in th e is o la t e d lig n in
by P h i l l i p s e t a l . (2 9 ) .
There i s not much change, however, in th e percentage o f the t o t a l
m ethoxyl groups which are a ss o c ia te d w ith tl^ lig n in is o la t e d from th e
f e c e s o f cows fe d orchard grass hay cu t a t four sta g es o f m atu rity.
would su g g est th a t th ere i s a higher d i g e s t i b i l i t y o f th e n o n -lig n in

This

104

m ethoxyl in th e immature forage and t h is i s ev id en t i n a comparison o f th e
d ig e s t io n c o e f f i c i e n t s o f th e various fr a c tio n s o f th e methoxyl groups th a t
are a ls o given in Table 26*

D i g e s t i b i l i t y o f th e t o t a l m ethojyl conten t

o f th e r a tio n and the methoxyl groups n o t a sso cia ted w ith th e lig n in both
d ecrea se w ith in c re a sin g m aturity o f the p la n t w hile th ere i s p r a c t ic a lly
no change in th e d i g e s t i b i l i t y o f the methoxyl groups a sso c ia te d w ith th e
lig n in ,
SUMMARY
The apparent d ig e s tio n c o e f f ic ie n t s o f lig n in in r a tio n s con tain in g
orchard grass hay c u t a t fou r sta g e s o f m aturity ranged from 3 ,8 to 16,0
p e r c e n t.
The lig a in s is o la t e d from four sta g e s o f orchard grass o f in c r e a sin g
m atu rity had n itr o g en con ten ts o f 4 ,2 5 , 4 ,1 5 , 3,53 and 2,41 p e r ce n t.

The

average n itr o g en co n ten ts o f the lig a in s is o la t e d from the corresponding
f e c e s were 5 ,1 9 , 4 ,1 3 , 3 ,6 2 and 2,91 p e r ce n t.

Apparently no degradation

o f th e n itr o g en a sso c ia te d w ith th e lig n in in orchard grass hay occurred
during d ig e s t io n by d airy cows.

There may be erro rs in the determ in ation

o f l ig n i n th a t are unaccounted fo r in the a n a ly s is o f m a ter ia ls d iff e r in g
w id ely in other c o n s tit u e n t s .
The apparent d ig e s tio n c o e f f ic ie n t s fo r the l ig n in corrected fo r n it r o ­
gen co n ten t was somewhat higher (7 ,5 to 19.8 p ercen t) than the d ig e s tio n
c o e f f i c i e n t s fo r crude lig n in .
The benzoic a cid e x c r e tio n in the urine per 100 grams o f lig n in fed
was lower when feed in g the most mature hay than when feed in g th e other
th ree l e s s mature hays.

There was no r e la t io n between the d ig e s tio n co­

e f f i c i e n t o f l ig n i n and the urinary e x c r e tio n o f benzoic a c id .
The t o t a l methoxyl con ten t o f the hay fed was lower than th e t o t a l
m ethoxyl con ten t o f corresponding fe c e s on a dry m atter b a s is .

The methoxyl

105

c o n te n ts o f the l ig n i n is o la t e d from the various hays was higher than the
m ethoxyl co n ten ts o f the lig n in is o la te d from the corresponding f e c e s .
The p ercen t o f the t o t a l methoxyl content in the hay th a t was a sso c ia te d
w ith th e l ig n i n in crea sed w ith in crea sin g m aturity o f the orchard g r a ss.
Higher p ro p ortion s o f th e t o t a l methoxyl content o f the f e c e s was a sso c ia te d
w ith the l i g n i n in th e fe c e s and o n ly s lig h t changes in t h i s percentage
©ocurred when hays o f a wide range o f m aturity were fe d .
D i g e s t i b i l i t y o f th e t o t a l methoxyl content and the n o n -lig n in methoxyl
con ten t o f th e r a tio n decreased w ith in creasin g m aturity o f the orchard
grass hay.

D ig e stio n o f th e lig n in methoxyl groups ranged from 20.3 to

3 1 .6 p ercen t and showed no c o n siste n t trend in r e la t io n to the stage o f
m atu rity o f the hay fe d .

106

literature cited

1*

Adams, G* A* , and A. E. Castagne.
D is tr ib u tio n o f methoxyl and uronic aoid groups in c e r e a l
straw s. Can. J. Research, B, 27:924-932, 1949.

2.

Armstrong, D. G ., H. Cook and B. Thomas.
The lig p in and c e llu lo s e con ten ts o f c e r ta in grassland sp e c ie s
a t d if f e r e n t sta g e s o f growth. J. Agr. S c i . , 4 0 :9 3 -9 9 , 1950.

3.

A s so c ia tio n o f O f f ic ia l A g ricu ltu ra l Chemists.
O f f i c i a l methods o f A n alysis o f the A sso c ia tio n o f O f f ic ia l
XgrTcuIH;ura3^^Eeml^t^"'Washin'^onM? ,,' I)*.' C. "TEE E3T. T*T£f.—

4.

Bondi, A* H*, and H. Meyer.
L ignins in young p la n ts.

5.

6.

Biochem. J . , 43:248-256, 1948*

Clark, E. P.
XLI. M icrochemical methods.
22:100, 1939.

J. A ssoc. O ff. Agr. Chemists.

C lark, E. P.
Report on m icroohem ical methods. Alkoxyl determ ination.
J . A ssoc. O ff. Agr. Chemists. 22:622-624, 1939.

7 . Corbin, J . E.
Unpublished t h e s i s , Univ. o f Kentucky, 1947. C ited by Forbes,
R. M., and W. P. Garrigus. J. Animal S c i . , 7:373-382, 1948.
8 . Crampto n , E. W.
P astu re s tu d ie s . XIV. The n u tr itiv e value o f pasture herbage.
Some problems in i t s e stim a tio n and some r e s u lt s thus fa r ob­
ta in e d a t MacDonald C o lleg e. S c i. A gr., 19:345-357, 1939*
9 . Crampto n , E. W., and L. A. Maynard*
The r e la t io n o f c e llu lo s e and lig n in to the n u tr it iv e value o f
animal fe e d s . J . N u tr itio n 15:383-395, 1938.
10. Csonka, F. A ., M. P h i ll i p s and D. B. Jones.
S tu d ie s on l ig n i n m etabolism . J. B io l. Chem., 8 5 :6 5 -7 5 , 1929.
11.

D a v is, R. E ., C. 0. M ille r and I . L. Lindahl.
Apparent d i g e s t i b i l i t y by sheep o f lig n in in (dehydrated) pea
and lim a bean v in e s . J* Agr. Research, 74:285-288, 1947.

12.

DeMan, T. J . , and J. G. DeHeus.
L ig n in in grass (w ith s p e c ia l reference t o the n itro g en p resen t
in th e lig n in p r e p a r a tio n ). Rec. Trav. Chem., 69:270-276, 1950.

13.

E l l i s , G. H ., G. Matron© and L. A. Maynard.
A 72-p ercen t s u lfu r ic acid method fo r the determ ination o f lig n in
and i t s use in anim al s tu d ie s . J. Animal S c i . , 5:285-297, 1946.

107

14.

F orbes, E. B ., R. p# E l l i o t , R. W. S w ift, W. H. James and V ivian
F. Smith.
V a r ia tio n in determ inations o f d ig e s tiv e ca p a c ity o f sheep.
J . Animal S c i . , 5*298-305, 1946.

15.

F ra n co is, A ., A. M. Leroy and Genevieve Levy.
Le so r t d es radicaux methoxy au cours de la d ig e s tio n des
p e c tin e s e t lig n in e s par l e s B ovins. Comp. r e n d ., 232*13251325, 1951.
^

16.

Gray, F. V.
The d ig e s tio n o f c e llu lo s e by sheep. The e x te n t o f c e llu lo s e
d ig e s tio n a t su ccessiv e le v e ls o f the alim entary tr a c t . J.
Expt. B io l* , 24*15-19, 1947.

17.

H ale, E. B ., C* $T* Duncan and C. F. Huffman.
Rumen d ig e s tio n in the bovine w ith some ob servation s on the
d i g e s t i b i l i t y o f a l f a l f a hay. J . Dairy S c i . , 23:953-967, 1940.

18.

Juon, P.
Uber den E in flu s s der Futterkonservierung auf d ie Be stand t e i le
der Zellwand. Landw. V ers. S t a ., 120*129-224, 1934.

19.

Kane, E. A ., W. C. Jacobson and L. A. Moore.
A comparison o f techn iqu es used in d i g e s t i b i l i t y stu d ies w ith
d a iry c a t t l e . J. N u tr itio n , 41*583-596, 1950.

20.

K ingsbury, F. B. and W. W. Swanson.
A rapid method fo r determ ination o f hippuric acid in u r in e .
J. B io l. Chem. 48*13-20, 1921.

21.

Louw, J. G.
The r e la t iv e d i g e s t i b i l i t y o f the c o n stitu e n ts o f the carbo­
hydrate complex o f g ra sses a t su c c e ssiv e sta g e s o f growth w ith
referen ce to th e ir p a r titio n in to crude fib e r and n itr o g e n -fr e e
e x tr a c t according to the standard method for fe e d in g s tu ff
a n a ly s is . Onderstepoort J. V e t. S c i. 17*165-179, 1941.

22.

McAnally, R. A.
D ig e stio n o f straw by th e ruminant.
1942.

Biochem. J . , 36*392-399,

23.

Norman, A. G.
The a s s o c ia tio n o f xylan w ith c e llu lo s e in c e r ta in str u c tu r a l
c e l l u l o s e s . Biochem. J . , 30*2054-2072, 1936.

24.

Norman, A. G.
The com position o f forage crops. I I I . C ocksfoot. Changes m
the herbage during growth, with and w ithout a d d itio n s o f n it r o ­
genous f e r t i l i z e r . Biochem. J. 33*1201-1208, 1939.

25.

No m a n , A. G ., and S. H. Jenkins.
The determ ination o f lig n in . I I . Errors introduced by the
presence o f p r o te in s . Biochem. J . , 28*2160- 2168, 1934.

108

26*

Paloheim o, L.
B eitrage zur Ligninbeslsiinnrung mit Saurehydrolyse.
214:161-174, 1929.

Biochem. Z .,

27.

Pazur, J . H ., and W. A. DeLong.
P asture s tu d ie s . XXVTII. E ffe c t o f lig n in content and o f stage
o f maturi-ty o f dry clo v er forage on the urinary e x cr etio n o f
aromatic a c id s by sheep. S c i. A g r., 28:39-46, 1948.

28.

P h i l l i p s , M.
The quant i t a t i ve determ ination o f m ethoxyl, lig n in and c e llu lo s e
i n p lan t m a te r ia ls . J. A ssoc. O ffic . Agr. Chemists. 15:118-131,
1952.

29.

P h i l l i p s , M.
S tu d ies ©n the q u a n tita tiv e e stim a tio n o f lig n in . I I . E ffe c t
©f c e r ta in p r o tein s on th e determ ination o f lig n in by the fuming
HC1 method. J. A ssoc. O ffic . Agr. Chemists. 22*422-427, 1939.

SO.

P h i l l i p s , M., J. Davidson and H. D. Weihe.
S tu d ies o f lig n in in wheat straw with referen ce to lod gin g.
J . Agr. S c i . , 43:619-626, 1931.

31.

P h i l l i p s , M., B. L. Davis and H. D. Welhe.
Composition o f the tops and r o o ts o f th e tim othy p la n t a t
su c c e ssiv e sta g es o f growth. J. Agr. Research. 64:533-546,
1942.

32.

P h i l l i p s , M., and M. J. Goss.
Composition o f the le a v e s end sta lk s o f b arley a t su cc essiv e
sta g e s o f growth, w ith sp e c ia l reference to the form ation o f
lig n i n . J. Agr. Research, 51:301-319, 1955.

33.

P h i l l i p s , M., M. J. Goss, B. L. Davis and H. S tev en s.
Composition o f the variou s p a rts o f the o a t p la n t a t su c c e ssiv e
sta g e s o f growth, w ith sp e c ia l referen ce to th e form ation o f
lig n in . J. Agr. Research. 59:319-366, 1939.

34.

P h i l l i p s , M., H. Weihe, D. B. Jones and F. A. C s o n k a .
The dem ethoxylation o f lig n in in the anim al body.
B io l. M ed., 26:320-321, 1929.

35.

R it t e r , G. J .
Chemistry o f Wood. VTI. R ela tio n between methoxyl and lig n in
in wood. Ind. Eng. Chem., 15:1264-1266, 1923.

36.

R ogozinsk i, F ., and M. Starzewska.
Tiber d ie Verdauung des Lignins bei den W iederkauem.
Acad, p olon . S c i. B, 1243-1252, 1928.

37.

S ton e, J . E ., M. J. B lundell and K. G. Tanner.
The fo n a a tio n o f lig n in in wheat p la n ts . Can. J. Chem. 29:
734-745, 1951.

Proc. See.

B u ll.

109

38.

S w ift, R. W. , E. J . Thacker, A* B lack, J* ^ B ra tzler and W. H. James#
D i g e s t i b i l i t y o f ration s fo r ruminants as a ffe c te d by proportion
©f n u t r ie n t s . J . Animal S c i# , 6:432-444, 1947.

39.

Thomas, B#, and D. G. Armstrong.
A study o f some methods at presen t used fo r the determ ination o f
l i g n i n . J . Agr. S c i . , 59:335-346, 1949.

40.

Waksroan, S . A ., and S tev en s, E# R#
A system o f proximate chemical a n a ly sis o f p la n t m a te r ia ls .
Ind# Eng. Chem. Anal. Ed. 2:167-173, 1930.

41.

WDodman, H. E ., and J . Stew art.
The mechanism o f c e llu lo s e d ig e s tio n in th e ruminant organism .
I I I . The a o tio n o f c e llu lo s e s p lit t in g b a c te r ia on the fib r e
o f c e r ta in ty p ic a l fe e ding s t u f f s . J . Agr. S c i . , 22:527-547,
1932#

T ABLES

110

T a b le 2 2 .

Crude L ignin Fed and Excreted by Each
An imal R eceiving Various S tages o f
Orchard Grass Hay p lu s Grain#

Average D a ily Crude
Lignin Consumed
Ifay
Grain
T otal
gms.
gms.
gms.

Average
D aily
Lignin
Excreted
gms.

'
Lignin
Recovery
%

Lignin
D igested
%

Hay Fed

Animal

Stage 1

X65
2408
N635

781*0
812.3
499*8

10.3
1 8 .4
14*4

791.3
830.7
514.2

741.8
763.9
479.7

93.7
92.0
93.3

6 .3
8 .0
6 .7

Stage 2

X65
2408
N635

695*6
723*4
445*2

1 0 .3
1 8 .4
14.4

705.9
741.8
459.6

660.8
623.2
408.7

93.6
84.0
88.9

6 .4
1 6 .0
11.1

Stage 3

X65
2408
N635

816.3
848*9
532.4

10.3
1 8 .4
14*4

826. 6
867.3
536.8

795.4
754.8
480.0

9 6 .2
8 7.0
8 9 .4

3.8
13.0
1 0 .6

Stage 4

X54
2408
N635

696*9
1006.6
619*4

15.5
1 8 .4
1 4 .4

712.4
1025.0
633.8

624.5
886.0
578.2

8 7 .7
8 6 .4
9 1 .2

1 2 .3
1 3 .6
8 .8

I ll

T a b le 2 3 .

n itr o g en Content o f Crude Li gain Is o la te d from
Various Stages of Orchard Grass Hay and the
Corresponding Feces

Stage o f
M aturity

Stage 1

Stage 2

Stage 3

Stage 4

M aterial

Hay

Animal

-------

Crude
Lignin

Hitro gen

True*
Lignin

%

%

%

7.77

4 .2 5

5.71

F eces

X65
2408
N635

21.61
20.20
20.63

5 .07
5 .16
5.34

14.77
13.69
13.74

Hay

-------

6.74

4 .1 5

5.00

Feces

X65
2408
N635

19.04
16.99
17.63

4 .3 5
4.07
3.98

1 3.23
12.11
12.71

Hay

-------

7.97

3.53

6.21

F eces

X65
2408
U635

19.32
17.36
18.12

3.49
3. 69
3.67

14.92
13.18
13.36

Hay

-------

9 .6 6

2.41

8 .1 2

F eces

X54
2408
N635

18.83
17.88
18.64

3.18
2.69
2.85

15.09
14.72
15.25

\ f Crude L ignin minus (U x 6 .2 5 )

112

Table 24.

True Li gain Fed and Excreted by Each Animal
R e c e d in g Various Stages of Orchard Grass Hay
p lu s Grain

Average D a ily True
Lignin Consumed
Say
(jrain
T otal
©ns*
gpos.
gms.

D a ily
Li gain
Excreted
gms.

Lignin
Recovery
%

Lignin
D igested
%

Hay Fed

Animal

Stage 1

X65
2408
H635

573.4
596.4
367.0

10.0
18.0
14.1

583.4
614.4
381.1

507.0
517.7
319.5

86.9
84.3
83.8

13.1
15.7
1 6 .2

Stage 2

X65
2408
N635

515.3
535.9
329.8

10.0
18.0
14.1

525.3
553.9
343.9

459.2
444.2
294.7

8 7 .4
80.2
85.7

12.6
19.8
14. 3

Stage 3

X65
2408
H635

636.3
661.7
407.2

10.0
18.0
14.1

646.3
679.7
421.3

597.8
573.1
353.9

9 2 .5
8 4 .3
84.0

7 .5
1 5 .7
16.0

Stage 4

X54
2408
H635

592.0
855.1
526.2

15.2
18.0
14.1

607.2
873.1
540.3

500.4
729.4
474.1

8 2 .4
8 3 .5
8 7 .8

17.6
1 6.5
1 2 .2

115

T ab le 25*

U rinary E xcretion o f Benzoic Acid by Animals Fed
Orchard Grass Hay Cut a t Four Stages o f M aturity

Stage
and
Animal

Average
D a ily
Crude L ign in
Fed D ig e ste d
©as.
gms.

Aver a g e ______ Benzoic Acid E xcretion _______
D aily
Gns/100 gms.
Gms./lOO gms.
True L ignin
T otal
Crude Lignin
True Li gain
Fed D igested D aily ffed. D igested Fed toigestecT
gms.
©as.
©ms.

Stage 1
X65 791
2408 831
H655 514

4 9 .5
66.8
34.5

583
614
381

76.4
96.7
61.6

139
115
80

17.6
13.8
15.6

280.8
172.2
231.9

23.8
18.7
21.0

181.9
118.9
129.9

Stage 2
X65 706
2408 742
N635 460

4 5 .1
118.6
50.9

525
554
344

66.1
109.7
49.2

136
156
115

19.3
21.0
25.0

301.6
151.5
225.9

25.9
28.2
33.4

205.7
142.2
233.7

Stage 3
X65 827
2408 867
N635 537

3 1 .2
112.5
56.8

646
680
421

48.5
106.6
67.4

122
118
97

14.8
13.6
18.1

391.0
104.9
170.8

18.9
1 7 .4
23.0

251.5
110.7
143.9

Stage 4
X54 712
2408 1025
N635 654

8 7 .9
139.0
55 .6

607
873
540

106.8
143.7
66. 2

104
92
61

14.6
9 .0
9 .6

118.3
66.2
109.7

17.1
10.5
11.3

97 .4
64.0
92.1

114

T a b le 2 6 .

Methoxyl Content o f th e Feed and F eces Dry Matter and "the L ignin
I s o la te d from th e se M a teria ls, and D ig e stio n C o e ffic ie n ts fo r
Various F raction s o f Methoxyl Groups

Stage
and
M aterial

Animal

Stage 1
Hay
F eces

7,84

31.9

X65
2408
N635

1 .8 4
1*77
1 .7 2

7 .75
7.39
7 .7 0

63.6
59.3
63.4

58.4
59.7
61.0

16.0
23.5
21.5

7 7 .3
7 5 .4
7 9 .2

AV*

1.78

7 .6 1

62.1

59.7

20.3

7 7 .3

1.51

10.60

35.1

X65
2408
H635

2.09
2.08
2.08

8.80
8.78
8.88

5 8 .4
5 3 .4
56.7

5 6.4
57.8
57.9

28.4
35.1
31.3

70.8
69.1
7 1 .3

At .

2.08

8 .8 2

56.2

57.4

31.6

7 0 .4

1 .6 2

10.73

40.7

X65
2408
N635

2.25
2.08
2.40

9.30
8.68
9.52

6 2 .2
57.2
5 5 .4

47.5
52.7
4 7 .4

20.7
33.0
27.2

65.2
6 5.3
59.9

At *

2.24

9.17

58.3

4 9.2

27.0

63.5

1.85

10.41

45.4

2408
H635

2.35
2.50

9 .77
9 .9 6

60.9
59.6

45.5
4 2 .4

22.8
17.7

62.8
6 0 .6

Av*

2.43

9.87

60.3

44.0

20.3

61.7

Stage 3
Hay
F eces

Stage 4
Hay
F eces

i

1.41

Stage 2
Hay
F eces

T otal
Methoxyl

Lignin
D ig estio n C o e ffic ie n ts
Methoxyl
lionL ignin
in
T otal
Lignin
L ignin
Methoxyl Total Methoxyl Methoxyl Methoxy
%
%

FART III
A STUDY OF THE CRUDE FIBER AND NITROGEN-FREE EXTRACT FRACTIONS
OF ORCHARD GRASS HAY AND THE DIGESTIBILITY OF SOME OF
THE CONSTITUENTS BY MILKING COWS

INTRODUCTION

C ertain lim ita tio n s o f the ■widely used system o f fo o d s tu ffs a n a ly s is
inaugurated by Henneberg and Stohmann (2 2 ) have undoubtedly been recognized
s in c e the method was f i r s t proposed*

The value and u sefu ln ess o f t h is

system o f a n a ly s is has a ls o been recognized and demonstrated through many
y ears accum ulation o f r e s u lt s on a wide v a r ie ty of feed m a te r ia ls .

The

e x te n s iv e com p ilation o f feed com position and d i g e s t i b i l i t y data by
M orrison (36) and Schneider (44) are a tr ib u te to the p a st and p resen t
u s e fu ln e s s o f th e Henneberg system o f feed an alysis*

The stu d ie s o f

A xelsson (3 , 4 , 5 , 6 , 7 ) , D ijk str a ( 1 2 ) , DuokwoHh ( 1 3 ) , H allsw orth (2 0 ) ,
Homb (2 4 , 2 5 ), J a r l (2 6 , 2 7 ), Lancaster ( 2 9 ) , McMeekan (3 4 ), N ordfeld t
e t a l . (37) and O lofsson (40) a l l in d ic a te d e f in it e value in determ ining
th e crude fib e r con ten t o f fe e d s sin ce the high n eg a tiv e c o r r e la tio n be­
tween the crude fib e r con ten t and the d i g e s t i b i l i t y and fee d in g value o f
a fe e d c e r ta in ly j u s t i f y the continued u se o f the crude fib e r determ ina­
t io n in the absence o f a more d esirab le scheme o f an a ly sis*
There are numerous rep o rts in the lite r a t u r e d is c u ssin g the m erits
and lim it a tio n s o f p a r titio n in g th e carbohydrates o f fe e d s in to crude
f ib e r and n itr o g e n -fr e e e x tr a c t f r a c t io n s .

Several authors ( 8 , 9 , 10,

29, 31, 33, 35, 37, 38, 39, 49, 51) have c r it ic iz e d the Weende system
o f determ ining the content o f crude fib e r in a feed and c a lc u la tin g the
amount o f n itr o g e n -fr e e e x tr a c t as being u n s a tis fa c to r y p r in c ip a lly be­
cause th e c o n s titu e n ts th a t make up th e crude fib e r and n itr o g e n -fr e e
e x tr a c t fr a c tio n s vary g r e a tly w ith d if f e r e n t p la n t sp e c ie s and d iffe r e n t
m a te r ia ls and a ls o w ith d if f e r e n t co n d itio n s o f determ ining the crude
f ib e r f r a c t io n .

117

Crampton and Maynard (10) have compared the average d ig e s tio n co­
e f f i c i e n t s o f th e n itr o g e n -fr e e e x tr a c t and crude f ib e r fr a c tio n s in
v a rio u s c la s s e s o f fe e d s .

Dry roughages, pasture herbage and s ila g e had

3 9 , 6 7 , and 28 p e r ce n t, r e s p e c tiv e ly , o f th e cases in which the crude f ib e r
was a s h igh or h igh er in d i g e s t i b i l i t y than the n itr o g e n -fr e e e x tr a c t .
This demonstrated the v a r ia b il i t y in th e com position, d i g e s t i b i l i t y , and
fe e d in g v a lu e o f crude fib e r from various sou rces.
Norman (38) poin ted out th a t crude fib e r determined by th e conven­
t io n a l method was not a s in g le compound but c o n siste d o f c e llu lo s e and
l ig n i n w ith some h em ice llu lo se and p e c tin .

Several m o d ifica tio n s o f the

Weend e system o f a n a ly s is f o r crude f ib e r have been proposed but th ey
a l l have th e same c r itic is m even though the r e p r o d u c tib ility i s s a t i s ­
fa c to r y .

N o rd feld t e t a l . (37) compared se v e r a l methods fo r th e de­

term in a tio n o f crude fib e r and found them to give good r e p r o d u e tib ility
but d if f e r e n t methods gave d iffe r e n t v a lu es fo r crude f ib e r .

They a lso

showed th a t the com position o f the crude fib e r was d if f e r e n t in d iffe r e n t
fe e d s and the crude fib e r from a p a r tic u la r feed was d iff e r e n t from th a t
o f th e corresponding f e c e s .

They also demonstrated a s e le c t iv e d ig e s t­

i b i l i t y o f th e lig n i n , c e llu lo s e and pentosan fr a c tio n s which are the
main components o f th e crude f ib e r .

T his work emphasized the value o f

l ig n i n , c e llu lo s e and pentosan determ inations to supplement the crude
f ib e r determ ination and thus would give more u se fu l inform ation o f the
nature o f the carbohydrate fr a c tio n in feed s and f e c e s .
Knowledge o f th e se lim ita tio n s a sso c ia te d w ith the determ ination
o f crude fib e r has stim u lated in t e r e s t in other system s o f f e e d s t u f f s
a n a ly s is th a t would not lea v e such a large p o r tio n o f the feed a n a ly ti­
c a l l y undetermined.

A few in v e s tig a to r s have attempted to account fo r

118

n e a r ly a l l th e dry m atter of various feed s and fe o e s by a n a ly tic a l d e te r ­
m inations -which lea v e com paratively sm all amounts o f undetermined sub­
stan ces*
Probably th e e a r l i e s t stu d ie s o f the summative a n a ly s is o f common
fe e d in g s t u f f s in th e United S ta te s were done by Headden (21) and Widtsoe
and Stew art (50)*

Headden (21) p a r titio n e d c lo v er hay in to sugars,

d e x tr in s , sta r c h , x y la n s, lig n o n e s, c e l lu l o s e , m oistu re, ash , p r o te in s ,
m a te r ia ls ex tra cted by eth er and m a ter ia ls ex tra cted by a lco h o l and water
co rrected fo r sugar and dextrins*

Hie had 4 .8 percent o f th e t o t a l p la n t

m a ter ia l undetermined by t h is system o f a n a ly sis* Widtsoe and Stew art
(50) p a r titio n e d th e dry m atter o f a l f a lf a in to the e th e r e x tr a c t, water
e x tr a c t , a cid e x tr a c t , a lk a li e x tr a c t, f i b e r , and ash in the fib e r fr a c ­
tio n s*

They made p r o g r essiv e e x tr a c tio n s w ith each so lv e n t on the r e s i ­

due rem aining a f te r previou s e x tr a c tio n s thus accounting fo r a l l o f th e
dry matter*

This sytem would not be too u s e fu l for d i g e s t i b i l i t y stu d ie s

sin c e the m a teria l e x tr a c te d by each so lv en t from the feed and fe c e s
would probably vary w id ely .
Crampton and Whiting (11) proposed a scheme o f a n a ly s is which de­
term ined the percentage o f lig n in by d iffe r e n c e a fte r making a n a ly tic a l
d eterm in ation s o f c e llu lo s e and solu ble carbohydrates*

Ferguson (15)

analyzed wheat straw fo r i t s content o f ether e x tr a c t, crude p r o te in ,
a sh , lig n i n , tru e c e l l u l o s e , pentosans in c e llu lo s e and fur fur aldehyde,
m t h t h i s system o f a n a ly s is he had 1 3 .7 percent o f th e dry m atter un­
determined which he c a lle d "other carbohydrates”*

Ferguson (16) a lso

analyzed se v e r a l forage samples fo r the in d iv id u a l str u c tu r a l c o n s titu ­
e n ts o f th e c e l l w a ll and a lso the n o n -stru ctu ra l c o n stitu e n ts and
seoured v a r ia b le q u a n titie s o f undetermined c o n s titu e n ts .

A n alysis o f

119

"w&vy young M-gh p r o te in gross gave undetermined fr a c tio n s ©mounting to o n ly
4 .5 p ercen t o f th e dry m atter w hile the mere mature forages had over 16
p ercen t o f the dry m atter undetermined*

Reid (42) reported th a t la r g e r

amounts o f the dry m atter o f mature grass than o f younger grasses was un­
determ ined by the sum o f the lig n in , c e l l u l o s e , h e m ic e llu lo se , p e c tin ,
sta r c h , t o t a l sugar, a sh , crude p r o te in and eth er e x tr a c t percentages*
F landers (1 7 ) r e c e n tly reported a summative a n a ly s is o f tim othy hay
by determ ining a sh , b enzene-aloehol e x tr a c t iv e s , water e x tr a c t iv e s , p e c tic
su b sta n ces, h e m ic e llu lo s e s, alpha c e llu lo s e , lig n in and p rotein s*

A study

o f the fo u r h e m ic e llu lo se fr a c tio n s extracted in d ic a ted th a t th ey were
m ixtures and t h e ir com position varied from one p lan t source to another
(18)*

The h e m ic e llu lo se fr a c tio n s showed comparable v a r ia tio n s in the

u ron ic a c id anhydride and pentose conten ts w ith in p la n t fa m ilie s but n o t
between p la n ts o f d if f e r e n t fa m ilies*
The p re sen t sta tu s of our knowledge o f the carbohydrate c o n stitu e n ts
o f forage has been w e ll desoribed by P erciv a l (41) i n a recen t d is c u s s io n
o f th e s u b je c t.

He sta te d t h a t , "Although an immense amount o f routine

a n a ly t ic a l work has been carried out on forage crops in th e p a s t, we are
s t i l l ig n o r a n t, in th e main, o f what i s measured tinder such headings as
crude f i b e r , t o t a l carbohydrates and so on*tt
I t seemed d e sir a b le to study c e r ta in o f th e chem ical c o n stitu e n ts o f
the crude fib e r and n itr o g e n -fr e e e x tr a c t fr a c tio n s th a t could be d e te r ­
mined as e ith e r d e f in it e chem ical substances or th a t would be rep resen ta­
t iv e o f sim ila r substances when determ inations are made on w id ely d if f e r e n t
m a te r ia ls such as fee d s and feces*

While such a method o f a n a ly s is i s not

r e a d ily a p p lic a b le to rou tin e determ inations i t would give u s e fu l informa­
t i o n on th e r e la t iv e d i g e s t i b i l i t i e s o f variou s fr a c tio n s o f the carbo­
hydrate complex o f fo ra g e p la n ts and a lso might permit lo g ic a l grouping

120

o f c e r ta in o f th e se c o n stitu e n ts th a t would be b io lo g ic a lly sim ila r and
a ls o m ight be e a s i l y grouped fo r convenient chem ical determ inations#
The o b je c t o f t h is in v e s tig a tio n was to determine the d ig e s tio n co­
e f f i c i e n t s o f c e r ta in c o n stitu e n ts th a t are o r d in a r ily grouped in the crude
f ib e r and n itr o g e n -fr e e e x tr a c t fr a c tio n s and a lso to a sc e r ta in what per­
centage o f th e dry m atter o f the feed and fe c e s would be accounted fo r by
a more d e ta ile d system o f a n alysis#
EXPERIMENTAL PROCEDURE#
The method o f conducting the d ig e s tio n t r i a l s and the c o lle c t io n and
handling o f th e samples has been p r e v io u sly described (p a r t i)#
C e llu lo s e was determined by the method o f Matrone, E l l i s and Maynard
( 3 2 ).
Pentosans were determined as the fu r fu r a l y ie ld in g c o n stitu e n ts ac­
cording to the o f f i c i a l method o f th e A sso c ia tio n o f O f f ic ia l A g r icu ltu ra l
Chemists (1 ) and th e weight o f fu r fu r a l ph loroglu cid e c a lc u la ted as the
pentosan e q u iv a le n t.

The pentosan content o f th e crude Matrons c e llu lo s e

was determ ined on a sample o f crude c e llu lo s e which was d ivid ed in to
separate samples fo r determ inations o f th e pentosan and c e llu lo s e con­
te n ts.
Starch was determined on the grain samples by the o f f i c i a l d ia s ta s e
method w ith subsequent acid h y d ro ly sis o f the A sso cia tio n o f O f f ic ia l
A g r ic u ltu r a l Chemists ( 1 ) .

Starch was determined on the hay and fe c e s

samples by th e method o f H bffpauir (2 3 ).
D eterm inations o f the reducing sugars were made by e x tr a c tin g th e
m a ter ia l w ith 80 p ercen t a lco h o l according to the method o f Thomas, Melin
and Moore ( 4 8 ) , in v e r s io n w ith h yd rochloric a c id , and determ ining the
reduced copper a f t e r b o ilin g the e x tr a c t w ith copper s u lfa te - a lk a lin e

121

t a r t r a t e s o lu tio n by the d ich rom ate-ferric su lfate-diph en ylam in e procedure
d escrib ed by Ieonard e t a l . (3 0 ).
Organic a c id s were determined l y the method o f Somers (45)*

Aqueous

e x tr a c tio n s o f the m aterial were made in a Waring b lend er a fte r a d d itio n
o f s u f f i c i e n t 3 normal hydrochloric acid to bring the pH to approxim ately
1*0*

The a c id if ie d e x tr a c ts were heated in a steam bath to remove carbon

d io x id e , made to a convenient volume a t 25 degrees cen tigrad e and then a
50 m i l l i l i t e r a liq u o te ■was adjusted to pH 7*8 w ith sodium hydroxide (3 nor­
mal fo llo w ed by 0*05 normal sodium hydroxide) and t it r a t e d to pH 2 .6 w ith
0 .0 5 normal n i t r i c a c id .

The organic acid s were c a lc u la te d as th e equiv­

a le n t amount o f m alic acid*
RESULTS AND DISCUSSION.
The com position o f the crude fib e r and n itr e g en -free e x tr a c t fr a c ­
t io n s o f th e fee d s fed during the d ig e stio n t r i a l s conducted on the orchard
grass hay cu t a t fou r sta g es o f m aturity are given in Table 27.

The con­

v e n tio n a l proxim ate system o f a n a ly sis fo r feed s in c lu d e s determ inations
o f the p r o te in , a sh , eth er e x tr a c t, and crude fib e r percentages and c a l­
c u la tio n o f the n itr o g e n -fr e e e x tr a c t fr a c tio n o f th e feed by d iffe r e n c e .
W ith t h i s system , the percentages th a t were determined by d iffe r e n c e
(n itr o g e n -fr e e e x tr a c t) ranged from 35.0 to 4 5 .8 p ercen t of the dry m atter
o f th e h ays.

When an a ly ses were made o f the sugar, sta r c h , organic a c id ,

p en tosan , alpha c e llu lo s e and lig n in conten ts o f the hay th e undetermined
p o r tio n o f the t o t a l hay ranged from 8 .6 to 1 8 .5 percent o f the dry m atter.
These p ercen tages o f the undetermined p ortion o f th e dry m atter o f fee d s
are w ith in th e same range as reported by Ferguson (1 5 , 1 6 ).

Heid (4 2 )

accounted fo r somewhat higher percentages o f th e t o t a l dry matter o f
fo r a g e s.

122

A greater p ercentage o f th e dry m atter o f th e immature orchard grass
hay was accounted fo r by the more d e ta ile d system o f a n a ly s is than in th e
more mature orchard grass hay used in t h i s study*
rep orted by Reid (42)*

This trend has a ls o been

D iffer en ce s in the percent o f dry m atter accounted

f o r in th e immature and mature forages by t h is system o f a n a ly s is may be
p a r t i a ll y due t© th e in crease in the proportion o f th e dry m atter o f th e
hay which th e crude f ib e r and n itr o g e n -fr e e e x tr a c t fr a c tio n s rep resen t
w ith in c r e a sin g m aturity*

The t o t a l o f th e se two fr a c tio n s in crea sed from

61*9 p ercen t in th e immature hay to 76*2 percent in th e mature hay.

Errors

due t o con version o f the n itrogen conten t o f young p la n ts to p r o tein equiv­
a le n t may a ls o be greater in young p la n ts than in o ld e r plants*

I t i s a ls o

recogn ized th a t th e undetermined fr a c tio n in clu d es any a n a ly tic a l errors
in v o lv ed in each o f the in d iv id u a l analyses*

With the proximate system o f

a n a ly s is th e s e e rro rs are included in the n itr o g e n -fr e e exb ract fr a o tio n .
S ev eral authors ( 2 , 19, 28, 43, 4 7 , 52) have g iven summative an alyses
o f woods th a t are remarkably c lo s e to 100 percent o f th e o r ig in a l m aterial*
Most o f th e se experim ents have included th e t o t a l carbohydrate fr a c tio n o f
woods in p rep aration s o f h o lo c e llu lo se *

There i s evidence th a t properly

is o la t e d h o lo c e llu lo s e r e ta in s n e a r ly a l l o f the p en tosan s, a c e ty l groups
and the carbon d io x id e forming m a teria l o r ig in a lly p resen t in the wood, ( 4 3 ).
Another approach to th e summative a n a ly sis o f forages would be to in clu d e
se v e r a l ©f th e carbohydrate fr a c tio n s p resen t in forages in a s in g le de­
term in a tio n o f r e la te d m a ter ia ls such as th ose included in h o lo c e llu lo s e
p r e p a r a tio n s.

The f e a s i b i l i t y o f such a system would depend upon su ita b le

tech n iq u es for i s o l a t in g the h o lo c e llu lo s e fr a c tio n from forages and would
a lso n e c e s s it a t e a knowledge o f th e d i g e s t i b i l i t y o f the various c o n s titu ­
e n ts o f th e h o lo c e llu lo s e fr a c tio n *

1 25

The l ig n i n , t o t a l c e llu lo s e , and pentosan con ten t o f th e immature
orchard grass hay was lower than th a t o f the mature orchard grass hay*
The o rg a n ic a cid co n ten t o f the orchard grass hay decreased w ith advanc­
in g m aturity*

The sugar con ten t o f the most immature orchard grass hay

was low er than in th e hays c u t a t la te r sta g e s o f maturity*

The sugar

co n ten t o f th e hays cu t a t th e th ree la te r sta g e s o f m aturity p ro g ress­
iv e l y decreased w ith advancing maturity*

The low sugar oontent o f the

immature hay i s probably due to i t s b eing placed on th e bam dryer a t
a h igh er m oisture con ten t than th e other sta g e s thus p erm itting p la n t
c e l l r e s p ir a tio n to continue fo r a longer period than in the other th ree
sta g e s which were p a r t ia lly d ried in the f i e l d before being placed on
th e bam dryer*
The d e ta ile d com position o f th e crude f ib e r and n itr o g e n -fr e e ex­
t r a c t fr a c tio n s o f th e fe c e s o f each animal used in the d ig e stio n t r i a l s
i s shown i n Table 28*

The n itr o gen -free e x tr a c t in th e se fe c e s ranged

from 35*7 to 44*6 percent*

When a more d e ta ile d system o f a n a ly sis was

used in c lu d in g the detezm inations o f sugars, sta rch , organ ic a c id s , pento­
sa n s, alpha c e l l u l o s e , b eta and gamma c e l l u l o s e , and l i g n i n , the undeter­
mined p o r tio n o f the fe c e s dry m atter ranged from 0*1 to 9*6 percent*
The more d e ta ile d system o f a n a ly s is aocounted fo r a h i$ ie r percentage
o f the dry m atter o f f e c a l m a ter ia l than o f th e hays*
When orchard g ra ss hays o f in crea sin g m aturity were fed th e alpha
c e l l u l o s e , pentosan and lig n in con ten ts o f th e fe c e s in crea sed .

The in ­

crea se i n th e lig n in oontent o f the fe c e s i s small compared to th e change
in th e l ig n i n con ten t o f th e hays sin ce decreases in the d i g e s t i b i l i t y o f
th e t o t a l dry m atter reduce t h i s change.
The con ten t o f reducing sugars was very low in a l l o f the feces*
The sta r c h con ten t o f th e f e c e s ranged from 1*2 to 3*8 percent and showed

124

about th e same range o f v a lu e s fo r the th ree cows when fed each o f the
fou r orchard grass hays.
The c e llu lo s e aggregate is o la t e d from p la n t m a teria l by th e Matrons,
S i l l s and Maynard (3 2 ) method in clu d es a la rg e p art o f the h em icellu lo se
and r e la te d m a te r ia ls ■which are fu r fu r a l y ie ld in g c o n stitu e n ts and are
in clu d ed in the pentosan fr a c tio n in t h is study*

This does not perm it a

summative a n a ly s is o f th e forage to be made using th e crude c e llu lo s e
sin c e i t would d u p lic a te a p o r tio n o f th e pentosan fr a c tio n in the crude
c e l lu l o s e fra c tio n *

D eterm inations o f th e pentosan conten t o f crude

c e l lu l o s e is o la t e d by the method o f Matrone, E l l i s , and Maynard (3 2 ) were
made in order to c a lc u la te a "corrected Matrons c e l lu l o s e ” which was fr e e
o f pentosans and would n ot cause d u p lic a tio n in a system o f summative
a n a ly s is which a ls o included th e pentosan fraction *

Alpha c e llu lo s e was

determ ined on separate samples o f crude c e llu lo s e and the balance o f the
crude c e llu lo s e which was not determined as alpha c e llu lo s e and pentosans
was c a lc u la te d as b eta and gamma c e llu lo s e *
29*

These data are shown in Table

A pparently th e proportions o f alpha c e llu lo s e and pentosans in the

c e llu lo s e m a teria l is o la te d by the Matrone, E l l i s and Maynard (3 2 ) method
does n o t change ap p reciab ly w ith in crea sin g maturity*

Furthermore, th e

r a tio o f alpha c e llu lo s e to pentosans in th e crude Matrone C ellu lo se
is o la t e d from tlm f e c e s does not d i f f e r g r e a tly from th a t is o la t e d from
orchard g rass hay*

The fr a c tio n design ated as th e ”b eta and gamma c e llu ­

lo se " was c a lc u la te d as the resid u e from th e crude Matrone C e llu lo se th a t
was n o t determ ined as alpha c e llu lo s e or pentosans*

This fr a c tio n i s

q u ite v a r ia b le in th e amount p resen t in various m aterials*
The con ten t o f "corrected Matrone c e llu lo s e " fo llo w s the same trends
in th e hay and th e corresponding fe c e s as the crude Matrone c e llu lo s e *

125

The apparent d ig e s tio n c o e f f ic ie n t s o f th e various c o n stitu e n ts o f the
carbohydrate fr a c tio n and r e la te d c o n stitu e n ts are given in Table 30.

It

i s e v id e n t th a t the apparent d ig e s tio n c o e f f ic ie n t s o f the crude Matrone
c e l l u l o s e , corrected Matrone c e l lu l o s e , alpha c e l lu l o s e , h o lo c e llu lo s e ,
p e n to sa n s, t o t a l carbohydrate, organic acid s and undetermined fr a c tio n s a l l
decreased w ith advancing m aturity o f th e orchard grass hay.

The d i g e s t i b i l ­

i t y c o e f f i c i e n t s o f th e starch and sugar fr a c tio n s were h igh w ith a l l o f
the fou r sta g e s o f m atu rity,

A comparison o f the apparent d ig e s tio n co­

e f f i c i e n t s o f the crude Matrone c e llu lo s e and the corrected Matrons c e llu ­
lo s e would in d ic a te th a t there i s very l i t t l e d iffe r e n c e in the d i g e s t i b i l ­
i t y o f th e alpha c e llu lo s e and pentosan fr a c tio n s of the crude Matrone
c e llu lo s e .

A comparison of the apparent d ig e s tio n c o e f f ic ie n t s o f the

t o t a l pentosan f r a c t io n o f th e fee d and the crude Matrone c e llu lo s e in ­
d ic a te s th a t the pentosans not a sso c ia te d w ith th e crude Matron© c e l lu ­
lo s e had a somewhat lower d ig e s tio n c o e f f ic ie n t than th e pentosans in ­
cluded w ith th e crude Matron© c e l lu l o s e .
The apparent d ig e s tio n c o e f f i c i e n t s o f the undetermined fr a c tio n s
were c a lc u la te d by assuming th a t th e se fr a c tio n s were o f th e same com­
p o s itio n in

th e fee d and f e c e s .

The d i g e s t i b i l i t y o f th e undetermined

f r a c t io n o f the immature forage in d ic a ted th a t t h is fr a c t io n i s as h ig h ly
d ig e ste d a s th e sta r c h and sugar.

The d i g e s t i b i l i t y o f t h i s fr a c tio n de­

creased w ith in c r e a sin g m aturity and was d ig e ste d t o about the same ex­
t e n t as th e alpha c e llu lo s e in th e most mature stage o f orchard g r a ss.
A comparison o f th e d ig e s tio n c o e f f ic ie n t s o f the corrected Matrone
c e l l u l o s e , alpha c e l l u l o s e , h o lo c e llu lo s e , and pentosan fr a c tio n s o f any
one sta g e o f m atu rity o f orchard grass hay would in d ic a te th a t the d i­
g e s t i b i l i t y o f th e se groups are sim ila r enough to j u s t i f y grouping them

12 6

in to one fr a c t io n o f sim ila r substances such as mi girt "bo accomplished in
a h o lo c e llu lo s e determ in ation .

The o b je c t o f a more d e ta ile d a n a ly s is o f

th e carbohydrate fr a c tio n i s not to in crea se the a n a ly tic a l determ inations
n ec essa ry but to a llo w i n t e ll i g e n t grouping o f variou s c o n stitu e n ts in to
groups o f su bstances th a t would be sim ila r from an a n a ly t ic a l, b io lo g ic a l
and chem ical standpoint*
SUMMARY
A more d e ta ile d system o f a n a ly s is th a t included determ inations o f
th e sta r c h , su g a rs, organic a c id s , p entosans, alpha c e l lu l o s e , and lig n in
was used w ith orchard grass hay c u t a t four sta g es o f m aturity and the
corresponding f e c e s to study the c o n stitu e n ts o r d in a r ily grouped in the
crude f ib e r and n itr o g e n -fr e e e x tr a ct fra c tio n s*
A g rea ter percentage o f th e dry m atter o f the immature orchard grass
hay was accounted fo r by t h is system o f a n a ly s is than w ith the more mature
orchard grass hay used in t h i s study*
Higher p ercen tages o f th e dry m atter were accounted for by the de­
t a i l e d system o f a n a ly s is in the f e c e s o f animals fed th e immature orchard
g rass hay than in the fe c e s from animals fed the mature orchard grass hay*
Considerably higher percen tages o f th e t o t a l dry matter o f fe c e s were
determ ined by t h i s system o f a n a ly s is than were determined w ith the same
a n a ly t ic a l tech n iq u es on the forage fed to th e se animals*
C e llu lo se is o la t e d from the orchard grass hays cu t a t four sta g es o f
m aturity and from the corresponding fe c e s by the method o f Matrone, E l l i s
Maynard contained approxim ately 25 percent o f fu rfu ra l y ie ld in g con­
s t i t u e n t s c a lc u la te d as pentosans*

apparent d ig e s tio n c o e f f ic ie n t s

o f the c e llu lo s e corrected f o r pentosans was not app reciab ly d if f e r e n t
from th e d ig e s tio n c o e f f i c i e n t s o f the crude c e llu lo s e fraction *

127

The apparent d ig e s tio n c o e f f ic ie n t s o f the crude Matrons c e l lu l o s e ,
c o rr ec ted Matrons c e l l u l o s e , alpha c e l lu l o s e , p entosans, t o t a l carbo­
h y d r a te s, organic a cid s and undetermined fr a c tio n s a l l decreased w ith
advancing m atu rity o f the orchard grass hay.

The d ig e s tio n c o e f f ic ie n t s

o f th e sta r ch and sugar fr a c tio n s o f the orchard grass hay were high w ith
a l l o f the fou r sta g e s o f m aturity.
The s im ila r ity in the d ig e s tio n c o e f f ic ie n t s o f the alpha c e l lu l o s e ,
h o lo c e llu lo s e , pentosan, and crude Matrone c e llu lo s e fr a c tio n s in d ic a te
th a t a la rg e p a rt o f the forage th a t i s o r d in a r ily included in the crude
f ib e r and n itr o g e n -fr e e e x tr a c t fr a c tio n s could j u s t if i a b l y be grouped
in to a h o lo c e llu lo s e fr a c tio n th a t could be a n a ly t ic a lly determined*

128

LITERATURE CITED
1.

A s so c ia tio n o f O f f ic ia l A g ricu ltu ra l chem ists*
O f f ic ia l and T entative Methods o f A n alysis o f th e A sso c ia tio n
o r O f f i c i a l Agricultural^ Chemises. Seventh"~SdT%ron, 1950,

2*

A tch iso n , J . E*
In flu en ce o f cooking and b leach in g upon the chain len g th d i s ­
tr ib u tio n o f th e carbohydrate fr a c tio n in pulpwood. Paper
Trade J . , 116*23-34, 1943.

3.

A xels son, J.
The d ig e s tiv e cap acity o f ruminants. (Trans, t i t l e ) .
Biedermams Z en tra lb l. ( b ) Tiernahrung. 14*212-232, 1942.
Seen in a b stra c t o n ly . N u tritio n A b stracts and R evs., 12*684,
1943.

4.

Axe I s son, J .
The a n a ly s is and determ ination of the value of p a stu re. (Trans,
t i t l e ) . Svenska V a il. o . M osskulturf. K vartalsskr. 5*380-392,
1942. Seen in a b stra c t o n ly . N u tritio n A b stracts and R ev s.,
13*527, 1944.

5.

A x elsso n , J.
The a b i l i t y o f c a t t l e , ste e p , h orses and swine to d ig e s t the
n u tr ie n ts o f the feed in g s t u f f s . Ann. Roy. Agr. C o ll. Sweden,
16*84-100, 1949.

6.

A x elsson , J.
Connections between con ten ts o f n u tr ie n ts and d i g e s t i b i l i t y o f
grassland crop s. Kgl* Lantbrukshogsk. Ann., 17*320-341, 1950.

7.

A x elsso n , J . , and s* E rik sson.
The a v a ila b ilit y o f the method o f determ ination by d iffe r e n c e
o f the e f f e c t o f in d iv id u a l fe e d s . Some treatm ent o f European
m etab olic experim ents w ith growing p ig s . Kgl. Lantbrukshogsk.
Ann*, 17*161-203, I960.

8.

Browne, C« A.
The o r ig in and a p p lic a tio n o f th e term n itr o g e n -fr e e e x tr a c t in
the v a lu a tio n o f fee d in g s t u f f s . J. A ssoc. Off i e . Agr* Chemists,
23*102-108, 1940.

9*

Crampto n , E. W.
Some p astu re s tu d ie s . XIV. The n u t r it iv e value o f pasture
herbage. Problems in i t s e stim a tio n and some r e s u lt s thus fa r
ob tain ed a t MacDonald C ollege. S c i. A gr., 19*343-357, 1939.

10. . Crampto n , E. W., and L. A. Maynard.
The r e la t io n o f c e llu lo s e ani lig n in content to the n u tr itiv e
value o f animal fe e d s . J . N u tr itio n , 15*38 3-395, 1938.

129

11.

Crampton, E. W., and p. I h itin g .
A proposed scheme o f feed in g s t u f f s a n a ly s is .
2:278- 284, 1942.

J. A n im al S c i* .

12 *

D ijk s tr a , N. D.
The d i g e s t i b i l i t y and feed in g value o f a r t i f i c i a l l y dried
g r a ss. (Trans, t i t l e ) . V e r s l. Landbouk. Onderzoek., 1949.
Seen in ab stra ct o n ly . N u tr itio n A b stracts and Revs. 20:208209, 1950.

13.

Duokworth, J .
A s t a t i s t i c a l comparison of th e in flu e n c e o f crude fib e r on
the d i g e s t i b i l i t y o f roughage by bos in d icu s (Zebu) and bos
taurus c a t t l e . Trop. Agr. (T rin id ad ), 2 3 :4 -8 , 1946.

14.

E l l i s , G. H ., G. Matrone and L. A. Maynard.
A 72 p ercen t s u lfu r ic a c id method fo r th e determ ination o f
l ig n in and i t s use in animal n u tr itio n s tu d ie s . J. Animal
S c i . , 5:285-297, 1946.

15.

Ferguson, W. S.
The d i g e s t i b i l i t y o f Tidieat straw and wheat straw p u lp .
Biochem. J . , 36:786, 1942.

16.

Ferguson, w . S.
The a n a ly s is o f p lan t m aterial w ith p a r tic u la r referen ce to
s tr u c tu r a l c o n s titu e n ts . A g ric. P r o g ., 23:129-137, 1948.

17.

F lan ders, C. A.
H em icellu lo ses and summative a n a ly sis o f tim othy hay.
Biochem. B iop h ys., 36:421-424, 1952.

Arch.

18.

F lan d ers, C. A.
H em icellu lose fr a c tio n s o f some hays and straw s.
Biochem. Biophys. 36:425-429, 1952.

19.

Freeman, R. D ., and P eterso n , F. C.
Proximate a n a ly s is o f the heartwood and sapwood o f some
American hardwoods. Ind. Eng. Chem*, Anal* E d ., 13:803-805,
1941.

Arch.

.

H allsw orth , E. G.
The r e la tio n s h ip between the crude fib e r content o f pasture
and oth er fee d in g s t u f f s and t h e ir d i g e s t i b i l i t y and starch
e q u iv a le n t. J. Agr. S c i . , 39:254-259, 1949.

21

.

Headden, W. P.
A study o f a l f a l f a and some oth er hays.
S ta . B u ll. 39, 1897.

22.

Henneberg, J. W* J . , and F. Stohraann.
B eitrage zur Begrundung ein er r a tio n e lle r Futterung der
W eiderkauer. Braunschweig, H efta 1 und 2, 1860-1864.

20

Colo. Agr. Expt.

130

23.

H offp au ir, C arroll L.
33?810-815S^1950 in p la n ts *

O ff. A gric. Chem ists,

24.

Homb, T*
Rechorches sur la r e la tio n e x is ta n t en tre l a teneur en lignin©
e t l a d i g e s t i b i l i t e des fo u rra g es. Meld. Norges Landbruksh..
26:283-330, 1946.

25.

Homb, T.
The connection between the content o f lig n in and d i g e s t i b i l i t y
in animal fe e d s . (Trans, t i t l e ) . Norges Landbrukshogsk*
F orin gsforsok . 6 1 :1 -4 8 , 1946. Seen in a b stract o n ly .
N u tr itio n A b stracts anl Revs. 19:470, 1949.

26.

J a r l, F.
The e f f e c t o f the content o f p lan t fib e r on the d i g e s t i b i l i t y
and the n u trie n t value o f northern typ es o f hay. (Trans,
t i t l e ) . Nord. Jordbrugsforskning. 20 :1 -3 2 , 1938. Seen in
a b s tr a c t o n ly . N u tr itio n A b stracts and Revs. 9:222, 1939.

27.

J a r l, F.
D i g e s t i b i l i t y t r i a l s w ith c a t t l e . 2. Hay, fodd er, r o o ts ,
o ilc a k e s , and other feed s and hay from h arvestin g t r i a l s
a t A lnays. Kgl* Lantbrukshogsk. S ta t. H usdjursforsk.
Medd. No. 4 4 :1 -6 0 , 1950.

28.

Jayme, G.
Uber d ie H erstellu n g Von H o lo c ellu lo se n und Z e lls to f fe n
m it t e ls N atrium chlorit* C ellu losech em ., 20:43-49, 1942.

29.

L an caster, R. J .
M etabolism t r i a l s w ith New Zealand feed in g s t u f f s . IV.
The r e la t iv e sig n ific a n c e o f l ig n i n , c e llu lo s e and crude
f ib e r in the e v a lu a tio n o f fe e d s . N. Zealand J. S c i. T ech.,
25A:137-151, 1943.

30.

Leonard, R. H ., R. C. Meade and R. B. Dustman.
Determ ination o f sugars in apple t i s s u e . Some m o d ifica tio n s
o f th e usual procedures. Ind. Eng. Chem., Anal. E d ., 15:
5 79-582, 1943.

31.

Louw, J . G.
The r e la t iv e d i g e s t i b i l i t y o f the c o n stitu e n ts o f the carbo­
hydrate complex o f grasses a t su cc essiv e stages o f growth
w ith referen ce to th e ir p a r t itio n in to crude fib e r and
n itr o g e n -fr e e e x tr a c t according to th e standard method fo r
fe e d in g s t u f f a n a ly s is . O nderstepoort J. V et. S c i . , 17;
165-179, 1941.

32.

Matrone, G ., G. H. E l l i s and L. A* Maynard.
A m od ified Norman-Jenkins method for the determ ination o f
c e llu lo s e aid i t s use in th e ev a lu a tio n o f f e e d s t u f f s . J.
Animal S c i . , 5:306-312, 1946.

131

33.

Maynard, L. A.
H itro g en -free e x tr a c t in animal n u t r itio n .
Agr. Chem ists, 23:156-161, 1940.

J . Assoc. O ffic .

34.

McMeekan, C. P.
A note on th e r e la tio n sh ip between Orude fib e r and the d i­
g e s t i b i l i t y o f organic m atter. N. Zealand d. S c i. T ech.,
25A:152-153, 1943.

35.

M itc h e ll, H. H.
The e v a lu a tio n o f feed s on the b a sis of d ig e s t ib le and
m etab olizab le n u tr ie n ts . J. Animal S c i . , 1:159-173, 1942.

36.

M orrison, F. B.
Feeds and Feeding. 21st E d itio n .
PuFITsHxng‘T ^ V T '9 48.

37.

38.

Ith a ca . N. Y .. The Morrison

N o r d fe ld t, S . , 0 . Svanberg and 0 . Claes son.
S tu d ie s regarding the a n a ly s is of crude f ib e r .
Suecana, 3:135-177, 1949.
Norman, A. G-.
The com position o f crude f ib e r .
1935.

A cta. Agr.

J . Agr. S c i . , 25:529-540,

39.

Norman, A. G.
The a s s o c ia tio n o f xylan w ith c e llu lo s e in c e r ta in str u c tu r a l
c e l l u l o s e s . Biochem. J*, 30:2054-2072, 1936.

40.

O lo fsso n , S.
Net energy conten t o f pasture and the r e la tio n sh ip between
crude p r o te in content and feed in g v a lu e . Svenska B etes 0 .
V a llfo r e n Arsskr. 20:133-148, 1938. Seen in a b stra c t o n ly .
N u tr itio n A b stracts and Revs. 8 :882, 1939.

41.

P e r c iv a l, E. G. V.
The carbohydrate c o n stitu e n ts o f herbage.
6:104-110, 1952.

42.

R eid, J. T.
E valu ation o f roughages by chemical and b io lo g ic a l means.
Proc. C ornell N u tr itio n C on f., 57-68, 1950.

43.

R it t e r , G* J* and Kurth, E. F.
H o lo c e llu lo s e , t o t a l carbohydrate fr a c tio n of e x tr a c tiv e fr e e maple wood. I t* s is o la t io n and p r o p e r tie s. Ind. Eng.
Chem., 25:1250-1253, 1933.

44.

Sch n eid er, B. H«
Feeds o f th e World, Their D ig e s t ib ilit y and Composition.
M organtown,^" V a ., Y/1.' Va. Agr* Exp. S t a ., 1947*

B r it. J. Nut.

132

45.

Somers, G. F.
The in flu e n c e o f l i g h t , ton p eratu re, and some enzyme poison s
upon th e t o t a l organic acid content o f l e a f t is s u e o f
Kalanehoe Daigremontiana (Hamet anl P e r r ie r ). J. P lan t
P h y s io l., 26:1-18, 1951.

46.

T echnical A sso c ia tio n o f the Pulp and Paper Industry.
T en tative Standard, T 203, M-40.

47.

Thomas, B. B.
In improved method for the la r g e -s c a le laboratory preparation
o f h o lo c e llu lo s e , Paper I n d ., 26:1281-1284, 1945.

48.

Thomas, J. W., C. G. M elin and L* A. Moore.
D eterm ination o f sugar in forage p la n ts ,
1363-1365, 1949.

Anal. Chem., 21:

49.

W&ksman, S* A*, and K* R. S tev en s.
A system o f proximate chemical a n a ly sis of p la n t m a teria ls
Ind. Eng. Chem. Anal. E d ., 2:167-173, 1930.

50.

W idtsoe, J. A ., and J. Stew art.
The chem ical l i f e h is to r y o f lu c e m .
Expt. Sta. B u ll. 58, 1898.

51.

W illiam s, R. D*, and W. H. Olmstead.
A biochem ical method for determining in d ig e s tib le residue
(crude f ib e r ) in f e c e s : L ign in , c e l lu l o s e , and non-water
so lu b le h e m ic e llu lo s e s. J. B io l. Chem., 108:653-666, 1935.

52.

W ise, L. E.
Q u an titative i s o l a t io n o f h e m ice llu lo se from co n ifero u s woods.
P relim inary communication. Ind. Eng. Chem., Anal. E d ., 17:6364, 1945.

Part I I .

Utah Agr.

TABLES

134

T a b le 2 7 .

Composition o f th e crude F ib er and N itro g en -free E xtract
F raction s o f th e Feeds used fo r D ig e stio n T rials on Various
Orchard Grass Hays
Orchard Grass Hay
Stage
1

Stage
2

Stage
3

Stage
4

24.8

15.8

13.0

1 2 .4

9 .2

Ash

9 .3

6 .8

7 .1

7 .2

3 .9

Ether E xt.

4 .0

3 .5

3 .9

4 .2

3 .6

Sugars

2.1

9 .5

5 .4

2 .4

1 .4

Starch

1 .2

1 .4

0 .8

0 .9

65.0

Organic Acids

6 .3

6.0

5.4

5 .0

—

Pentosans

1 5.1

15.8

16.8

1 8 .1

6 .4

Alpha C e llu lo se
Beta & Gamma
C e llu lo se

19.5

19.8

1 9.1

27.7

2.3

3 .4

5 .4

3.8

2.5

L ignin

5 .7

5 .0

6 .2

8 .1

0 .5

Undete rmined

8 .6

11.0

18.5

11.5

7 .7

Crude F iber

26.9

28.2

31.8

35.0

2 .2

N. F.E.
T otal
, v
Carbohydrates^1 '

35.0

4 5.7

4 4 .2

4 1 .2

81.1

4 9 .9

63.0

6 4 .4

63.1

82.8

H o lo c e llu lo s e ^ ^

46.5

52.0

5 8 .2

59.8

16.4

P r o te in

No. 86
Grain

C1 )T o ta l Carbohydrates * (Crude Fiber + N.F .E .) - (Lignin * Organi'
Aci<
^ ^ H o lo c e llu lo s e * Total Carbohydrates - (S tarch + Sugar)

135

LO

tO 03 CO

C
SO
P

t o O CD
H H

O W LO CO t> t o l .O Oi—I H
i—!

to O H

^

to

of Cows

P

03 COj
txci o
p
- p 02
CO
p

of the

Crude Fiber and N itrogen-free Extract Fractions of the Feces
Fed Orchard Grass Hay Cut at Four Stages of M a tu rity

LO

X

LO

CO

CO

w .

00

$
-p
CO

o

p

02
LO,

CO
lx!i

•

• •

• • •
P PC -

• '

1

t

DO O
•

•

CD CO p
•

•

•

02 CD CO

•

»

*

* O» 03
• H
• •LO• O ■ O ■CO
O tO LO CD 0 ^ L) CD
I I I—I

I—i

02 CO
•

»

02

p

CO 00
• •
COCO

02

P

COP p
• • •
02 P oP P

03 CD
p• CO
• • * 02• co• C-o CO
•
O p LO COC- p LO CD
p p
P

00 i—I
• •
p p
C2 P

LOto
• • LO•
02 t>
P P

to• to• 03• CO02
• * to•
o 02 CO LO LO to
p P

o « CD
•
CO
p
p

CD
• CO
•
C2 i—I
02 p

CO02• 02
•
•
CD 02 LP P

00 o
02• CO
• P• p•
m •
o to CO LO LO to
(—11—I

CD p
* •
to LO
p

02 i—
1
02 p

O•- p •f 03•
i—1C"
P i—1

! to• 02• p O
to* 02• LO• i—
•
» *
P
C
D
LO to LC c O
CO
1—1 l—I
p

LO

LO

0—r—(
• •

LO LO

■ •
p O
C2 p

COO
# a

o
p

LO
p

00 p
• •
CD CO

p

P

to•
O'
p

to•
LO
P

00

•
to
p

02•
P
P

p•
to
p

CO
•
CD
to

p• CO
•
to 1—I
p p

w

Xj
•H
O

o

•H

&
LO
col
col
02

- to c-• CO o• co» 02•
• O■
•
•
o 02 0 0 to C 2 LO NO to
p P
P

P* P•
CD P
P p

CD o
• •
O' p
to to

02• p•
03 CO ci—1 p

LO

CO LO 0 0

CO
•

CO
tiCjo
021

• • •
O 02 CO
02 P

LO

D- P to 03
1—t
• • • • • OD
• S>•- ■
t o t o p 02 c o to o- p
P
i—1

CD LO
• •
P
p p

to• 1—•I
o CO
p to

LO
CO
X]

02• C- CO
•
•
O to c02 p

02• P• p• 0 2• P• 0 3• 0 2• p •
O 02 0- p t o to P t o
1—1 1—I
P

to•
O
02

02•
tr­
ee

©,
cd
P

CO

00

02•
CO
tO

o

P

•rH

6

t©

3

CO

CD
•
p
to

p

p

o
P
t
cd

p

co

I
LO
CO

CD

P

Oi
©
L>
l
C|C
o
cd p
p 02:
CO

LO
CO
X

O•

o•
P C02 1—I
03
•

02• O• 02* LO• CV« O•
O 02 CO 1c—f o to
I—1

P• CD
•
P P
P

O'• C-•
p LO
P to

CO
• CO•
o- LO
02 02

• COto
• «
CD p o
02 p

!
t o i—
LO LO
to• CO
• p• * • LO• * *
o to 0 0 po p 02 P
P O
1—
1

* P•
P oP to

• CO
•
CO p
02 02

03 C- 1—1
• • •
p LO CO
02 p

LO LO LO
P
LO02
• • to• • • • P• •
O P 0 0 o P 02 LO P
I—
1 1—
1
P

CO o

CD
CO
• •
c - LO
02 02

LO

DO

• •
LO LO
i—I to

O

Jh
©

P
pr4

%

B
o
P

xl
p

Jh

o

Composition

©

Pi—
t

©

p
cd

i— !

t—!

ca

xd
-p

£
©
3:
-P
05

o
o

•

©©
©o
o

©
r_J

o
CO 1—i

©
p
o

©
P
© tP
PL,
F3

tcD cd
p P

•H.

c! ©
s£
o cd o
C
aj
H ©
■H P
o
c
d
© p
cd £ ©
fccO C! P hP So x)
Jh © i—( © H
-- c

u
©

a

p
©M
X? •
P (p

Sh •
OP

cd

P

©

P

cd

o
Eh

O

P

ro'c2’!
b 0
P ©
o

in

O

II

cd
■S
£

©

cd

©

p
o

©
p

ip

©

CO

©

o

O' P

Jh PP
P
©

o

cd o
p p
o o
E-h

P
cd
o
I—
1
cd

P

i—
I
©
O

o

p

o
Eh

02)

136

T a b le 29*

The Crude Matrone C e llu lo se Content o f Orchard Grass Hays and
th e Corresponding Peoes and the D is tr ib u tio n o f i t s Various C on stituents
C on stitu en ts o f Matrone C ellu lo se
Crude
Matrone
C e llu lo s e

Alpha
C e llu lo se

Pentosans
___

Beta &
Gamma
C ellu lo se

Corrected
Matrone
C ellu lo se (1 )

O.G. Hay
S¥g. 1

34*0

/O
62* 6

/a
26*3

11.1

25.1

S tg . 2

34*7

61*0

28.6

10 .4

24.8

S tg . 3

37*7

61*7

25.8

12.5

28.0

S tg . 4

40*3

67.5

26*4

6.1

29.7

Feoes
Stage 1
X65

17.8

6 1 .4

25.1

1 3 .5

13.3

2408

17.8

61 .4

25.1

13.5

1 3 .3

H635

16.8

5 8 .4

24.4

1 7 .2

12.7

Stage 2
X65

23.9

57.9

2 5 .4

16.7

17.8

2408

22.2

64 .2

27.4

8 .4

16.1

2J635

21.8

55.5

22.6

21.9

16.9

Stage 3
X65

2 6 .6

6 1 .6

25.4

13.0

18.8

2408

2 6 .2

6 1 .7

25.7

12.6

19.5

H635

27.1

61.6

25.2

1 3 .2

20.3

Stage 4
X54

27.7

67.1

26.8

6.1

20.3

2408

27.1

6 3 .5

24.2

1 2 .3

20.5

N635

27.2

60.8

24.7

14.5

20.5

137

T a b le 3 0 .
A p p aren t. D i g e s t i o n C o e f f i c i e n t s o f C a rb o h y d ra te s and R e la te d C o n s t i t u e n t s

H olo; c e ll u l o s e
1 ...................
i
t P en to san s

U ndeterm ined
F r a c tio n

A lpha
G e llu lo s e

82

82

80

82

78

97

96

86

-5 5

95

2408

82

81

80

83

79

94

97

87

52

99

N635

83

82

82

83

79

98-

94-

88

55

94

A'v.

82

88

Cl

70

96

96

87

53

96

S ta g e 2
X65

77

76

78

79

72

95

99

84

60

91

2408

79

78

77

79

75

95

98

85

58

82

N635

79

77

78

79

74

97

98

86

52

92

A v.

78

77

78

79

74

96

98

85

57

88

S ta g e 3
X65

72

73

69

73

64

97

98

79

52

85

2408

72

72

68

75

66

93

99

81

49

90

N655

72

71

69

74

67

97

98

82

48

87

A v.

72

72

69

74

66

96

98

81

50

87

S ta g e 4
X54

70

70

73

69

64

97

95

77

46

69

2408

69

68

73

69

63

94

93

76

45

77

N635

69

68

71

68

62

97

95

77

44

75

A v.

69

69

72

69

63

96

94

77

45

74

**

ho
P
1 CO

O rganic
A cids

C o rre c te d
C e llu lo s e

S ta g e 1
X65

S ta g e
and
Cow

S ta rc h

Crude
C e llu lo s e

T o ta l
C arbohydrate;

i n O rc h a rd G ra ss Hay C u t a t Four S ta g e s o f M a t u r i t y