THESIS

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This is to certify that the

dissertation entitled

FACTORS AFFECTING UTILIZATION OF SOYBEAN
PROTEINS INCLUDED IN MILK REPLACERS
FOR YOUNG CALVES

presented by

Aliomar Gabriel da Silva

has been accepted towards fulfillment
of the requirements for

Ph.D. Animal Science

degree in

 

 

 

J: w/\7‘//i/ (”Z (71/
1/ Major professor
J. T. Huber

 

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FACTORS AFFECTING UTILIZATION OF SOYBEAN
PROTEINS INCLUDED IN MILK REPLACERS
FOR YOUNG CALVES

BY

Aliomar Gabriel da Silva

A DISSERTATION

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Animal Science

1984

ABSTRACT
FACTORS AFFECTING UTILIZATION OF SOYBEAN

PROTEINS INCLUDED IN MILK REPLACERS
FOR YOUNG CALVES

BY

Aliomar Gabriel da Silva

First, twenty-four calves (8/treatment) were fed milk replacer
containing 19% crude protein (CP) from a) 100% milk protein (MP);

b) 66% modified soybean protein + 34% MP (MS); c) 66% heated soybean
flour + 34% MP (HS).

MP resulted in better gain and feed efficiency. Organic matter
and CP digestibility for MP, MS and HS were: 90.8%, 87.2%, and 85.3%;
and 82.6%, 72.1% and 64.1%, respectively.

A xylose absorption test was performed by feeding .5 g
D-xylose/kg body weight (BW) and a xylose disappearance test was
performed by intravenous injection of .25 g D-xylose/kg BW. Calves
fed MP had 16% greater xylose absorption than those fed MS or HS,
with a peak of 39.2 mg xylose/lOO ml plasma at 150 min after feeding
xylose. Calves fed soybean proteins showed greater capacity of
clearance of xylose from the blood.

Two calves/treatment were sacrificed and the small intestine
contents and structural integrity of villi were studied. Gastro-
intestinal tract contents were rapidly neutralized at the duodenum.

Greater acidity from the small to the large intestine contents were

Aliomar Gabriel da Silva

observed in calves fed soybean than MP, acidity of content of calves
fed HS was greater than M8. GP of content of the distal part of small
intestine was higher for calves fed soybean than MP. Wide morphological
variation in size and shape of villi were observed, with greater
differences within animals than between treatments.

Superior performance of calves fed MP was related to a greater
digestibility of nutrients and absorptive capacity of digested
nutrients. No reason was evident for higher blood xylose clearance
of calves fed soybean.

Second, sixteen calves were fed milk replacer (23% CP) from
a) 100% MP; b) 66% soybean protein concentrate + 34% MP (S). Eight
calves were sensitized to soybean and eight were not sensitized.
Afterwards each calf received one of the diets during 10 days followed
by the other for an additional 10 days.

Feeding S resulted in lower gain and feed efficiency. Higher
rectal temperatures, increased diarrhea and villi atrophy were observed
in calves fed S and suggested an allergic reaction to soybean protein

which were associated with the poor performance observed.

DEDICATION

In memory of my Mother (October 22, 1915 - July 8, 1983)

ii

ACKNOWLEDGMENTS

I would like to thank my major professor, Dr. J. T. Huber,
for his support and encouragement throughout my graduate program.
Also, I wish to express my appreciation to Dr. R. M. Cook,

Dr. J. L. Gill, Dr. T. Herdt, Dr. D. Hillman, and Dr. W. T. Magee
for serving on my Graduate Committee.

I would like to acknowledge the Empresa Brasileira de
Pesquisa Agropecuaria (EMBRAPA), Brazil, which provided financial
support for my graduate program and the Land O'Lakes, Inc., Webster,
IA which partially supported the research.

Last but not least, I wish to extend my deepest and most
sincere gratitude to my wife, Dulce, for her encouragement, love,
understanding and sacrifices during my course of study, research

and manuscript preparation.

iii

LIST OF TABLES .

LIST OF FIGURES

INTRODUCTION . .

REVIEW OF LITERATURE

Protein Digestion in

TABLE

Preruminant Calves

OF CONTENTS

Carbohydrate Digestion in Preruminant Calves

Soybean Proteins for Milk Replacers

Other Protein Sources for Milk Replacers

Summary of the Literature Review .

MATERIAL AND METHODS .

Experiment 1 .
Experiment 2 .

RESULTS AND DISCUSSION

Experiment
Experiment

CONCLUSIONS . .

APPENDICES . . .

BIBLIOGRAPHY . .

1
2

iv

viii

15
20
30
33
34

34
4O

46

46
80

89

91

104

Summary of dairy calves performance on different soybean
protein sources in milk replacer

Ingredient composition of milk replacers used in
Experiment 1 (% of spray dried material)

Chemical composition of milk replacers used in

Experiment 1

Ingredient composition of milk replacers used in
Experiment 2 (% of spray dried material)

Chemical composition of milk replacers used in

Experiment 2

Effect of feeding milk protein (MP), modified soybean
protein (MS), or heated soybean flour (HS) on calves
body weight (BW), total weight gain (TG) and gain as
a percent of initial body weight (% SW) of calves at

LI ST OF TABLES

different ages Experiment 1 .

Effect of feeding milk protein (MP), modified soybean
protein (MS), or heated soybean flour (HS), on
average daily gain (ADG), feed intake (FI), and
feed efficiency (G/I) of calves as measured for
each week of the experiment Experiment 1

Dry matter (DM), organic matter (OM), crude protein (CP),

ether extract (EE), nitrogen-free extract (NFE) and
ash digestibilities and nitrogen (N) retention in
two-week old calves fed milk protein (MP), modified

soybean protein (MS) or heated soybean flour (HS)

Experiment 1

Dry matter (DM), organic matter (OM), crude protein (CP),

ether extract (EE), nitrogen-free extract (NFE) and
ash digestibilities and nitrogen (N) retention in
five-week old calves fed milk protein (MP), modified

soybean protein (MS) or heated soybean flour (HS)

Experiment 1

21

36

37

42

43

47

48

56

58

10.

11.

12.

13.

14.

15.

16.

17.

18.

Effect of feeding milk protein (MP), modified soybean
protein (MS) or heated soybean (HS) on plasma urea
nitrogen (PUN) concentration of calves at different
ages Experiment 1 . . . . . . . . . . . . . . . . . . . .

Effect of previous feeding of milk protein (MP), modified
soybean protein (MS), or heated soybean flour (HS) on
average plasma xylose (XYL) concentration (mg XYL/

100 ml plasma) after oral dose of .5 g XYL/kg of
body weight was administered to 50-day old calves
Experiment 1 . . . . . . . . . . . .'. . . . . . . . . .

Percentage of oral or intravenous xylose (XYL) administered
which was excreted into the urine by calves fed milk
protein (MP), modified soybean protein (MS) or heated
soybean flour (HS) during a 5 hr period after XYL
administration Experiment 1 . . . . . . . . . . . . . . .

Effect of previous feeding of milk protein (MP), modified
soybean protein (MS), or heated soybean flour (HS) on
plasma xylose (XYL) concentration (mg XYL/lOO ml plasma)
after an intravenous dose of .25 g XYL/kg of body weight
was administered to 41 day old calves Experiment 1 . . .

Average log of plasma xylose (XYL) concentrations (mg XYL/
100 ml plasma) after an intravenous dose of .25 g XYL/kg
of body weight was administered to 41 day old calves fed
milk protein (MP), modified soybean protein (HS), or
heated soybean flour (HS) Experiment 1 . . . . . . . . .

Effect of feeding milk protein (MP), modified soybean
protein (MS) or heated soybean flour (HS) to calves
on pH, wet weight, dry matter, organic matter and
crude protein of contents from different sections
of the gastrointestinal tract, also on length of
small intestine and body weight Experiment 1 . . . . . .

Effect of feeding calves milk protein (MP), modified
soybean protein (MS) or heated soybean flour (HS)
on villi morphology Experiment 1 . . . . . . . . . . . .

Effect of feeding calves milk protein (MP), modified
soybean protein (MS) and heated soybean protein
(HS) on calves fecal scores and rectal temperatures
Experiment 1 . . . . . . . . . . . . . . . . . . . . . .

Effect of feeding milk protein (M) or soybean protein
concentrate (S) during the 21-day sensitization
period on calves body weights, body weight gains,
average daily gains, feed intakes, feed efficiencies
(gain/intake), rectal temperatures, fecal scores and
villi length Experiment 1 . . . . . . . . . . . . . . . .

vi

60

62

64

65

66

71

78

79

81

19.

20.

21.

A1.

A2.

A3.

Effect of sensitization (NS non-sensitized; SS =
sensitized), treatment (M = milk protein; S = soybean
protein concentrate) and experimental period (P1 =
period 1; P2 = period 2) on body weights (BW), average
daily gains (ADG), feed intakes (FI), feed efficiencies
(G/I), rectal temperatures (RT), fecal scores (FS) and
villi length (VL) of calves Experiment 2 . . . . . . .

Interaction of sensitization x period on average daily
gain (ADC) and feed efficiencies (G/I) of calves
mperiment 2 O O O O O O O O O O O O O O O O O I O O 0

Interaction of sensitization x treatment (M = milk
protein; S = soybean protein concentrate) on feed
efficiencies (G/I) and villi length (VL) of calves
Experiment 2 . . . . . . . . . . . . . . . . . . . . .

Analysis of variance for variables in Experiment 1 . . .

Analysis of variance for variables in Experiment 2
(21-day period) . . . . . . . . . . . . . . . . . . . .

Analysis of variance for variables in Experiment 2
(IO-day period) . . . . . . . . . . . . . . . . . . . .

vii

83

84

85

91

99

101

LIST OF FIGURES

Effect of feeding milk protein, modified soybean protein,
and heated soybean flour on body weight of calves at
different ages. For each age, points with different
letters are different (P<.05) Experiment 1 . . . . . .

Effect of milk feeding protein, modified soybean protein
and heated soybean flour on calves total body weight
of calves at different ages. For each age, points
with different letters are different (P<.05)

Experiment 1 . . . . . . . . . . . . . . . . . . . . .

Effect of feeding calves milk protein, modified soybean
protein, and heated soybean flour on body weight gain
as percent of initial body weight. For each age,
points with different letters are different (P<.05)
Experiment 1 . . . . . . . . . . . . . . . . . . . . .

Effect of feeding milk protein (MP), modified soybean
protein (MS), and heated soybean flour (HS) on
average daily gain of calves at different ages.
For each age, points with different letters are
different (P<.05) Experiment 1 . . . . . . . . . . . .

Effect of feeding milk protein (MP), modified soybean
protein (MS), and heated soybean flour (HS) on feed
intake of calves at different ages. For each age,
points with different letters are different (P<.15)
Experiment 1 . . . . . . . . . . . . . . . . . . . . .

Effect of feeding milk protein (MP), modified soybean
protein (MS), and heated soybean flour (HS) on feed
efficiency (body weight gain/feed intake) of calves.
For each age, points with different letters are
different: a,b,c (P<.OOS); d,e (P<.Ol) and f,g
(P<.10) Experiment 1 . . . . . . . . . . . . . . . . .

Effect of feeding milk protein (MP), modified soybean
protein (MS) and heated soybean flour (HS) on calf
plasma xylose concentrations at different times after
oral ingestion of .5 g/kg body weight. For each time
points with different letters are different: a,b
(P<.05) and c,d (P<.10) Experiment 1 . . . . . . . . .

viii

49

50

51

53

54

55

63

10.

11.

Effect of feeding milk protein (MP), modified soybean
protein (MS), and heated soybean flour (HS) on calf
plasma xylose concentration at different times after
IV dose. For each time, points with different
letters are different (P<.05) Experiment 1 . . . .

Effect of feeding milk protein (MP), modified soybean
protein (MS), and heated soybean flour (HS) on calf
plasma xylose concentration at different times after
IV dose. Data presented as linear regression of
log plasma xylose concentration on time Experiment 1

Normal villi from a scanning electron micrographs of
small intestinal mucosa of a calf. Most villi have
a fairly uniform appearance and surfaces show
transverse furrows with Goblet cell openings
Experiment 1 . . . . . . . . . . . . . . . . . . .

An abnormal villi from scanning electron micrographs
of small intestinal mucosa of a calf Experiment 1 .

ix

67

68

76

77

INTRODUCTION

Whole milk is generally considered the best feed for young
calves, however approximately 70% of dairy calves in the U.S. are
raised on milk replacers for economic reasons (Schugel, 1973). Milk
replacers are generally more expensive than colostrum or disposable
milk, but cheaper than saleable milk (Appleman and Otterby, 1973).
Properly formulated milk replacers, fed at recommended rates, have
been used for many years as satisfactory liquid diets for calves
after 3-5 days of age. Calves fed milk replacers normally do not
show as much bloom as calves fed whole milk or colostrum, but usually
make acceptable weight gains (Jones, 1975). Replacement of milk
products in calf milk replacers with plant and/or animal products
has been extensively utilized because of the increasing demand for
milk in human diets and the consequent high milk prices accompanying
this demand.

Soybean products are the most common non-milk source of
protein in calf milk replacers. Soybean flour is a finely ground
material resulting after screening the ground, dehulled, oil-extracted
meal. Soybean protein concentrate is prepared from dehulled ground
beans which have been fat-extracted and further extracted with ethanol
and water to remove water-soluble non-protein constituents. It must
have not less than 70% crude protein (Church, 1984). Soybean protein

concentrate and especially manufactured soybean flour are satisfactory

protein sources for milk replacers, provided they undergo sufficient
treatment to destroy the trypsin inhibitor factor.

The objective of the present study was to further elucidate
factors limiting the nutrient utilization of soybean products in milk

replacers for young calves and relate such factors to calf performance.

REVIEW OF LITERATURE

The digestive system of the young calf undergoes a rapid
transformation during the first few months after birth. The calf
is born a nonruminant and becomes a functioning ruminant by 6 weeks.
Economic reasons have lead to the development of milk replacers with
the objective of reducing the amount of whole milk used by the calf.
On the other hand it must be remembered that digestion of nutrients
is a complex process in that the food must pass through the alimentary
tract at a suitable rate to permit action of digestive enzymes in order
for normal absorption to occur.

The milk is the natural food for the calf, but studies to
replace the milk nutrients have not always been successful. Reviews
by several authors (Huber, 1969; Porter, 1969; Radostits and Bell,
1970; Roy, 1974) have shown that young calves are very sensitive to
protein quality during the first 3 weeks of life, but protein digest-
ibility increases with age allowing the use of some proteins of lower
quality than generally found in milk and milk products.

The objective of this review was to summarize various aspects
of protein digestion by young calf, especially that of alternative

sources such as soybean protein which has been used in milk replacers.

Protein Digestion in Preruminant Calves

 

Milk and milk-type liquids fed to young calves are shunted
directly into the abomasum through the esophageal groove. The rumen
is effectively bypassed when the animals consume their liquid diet
in a state of "juvenile excitement" (butting movement with heads,
tail wagging, etc.), but when the animals drink to quench thirst or
are forceably drenched, the liquids normally enter the rumen (¢rskov
et al., 1970). The nipple is more effective than open pail feeding
in stimulating reflex closure of the esophageal groove (Wise and
Anderson, 1939; Wadleigh and Mowat, 1978). Whey has been shown to be
a poorer stimulator of esophageal groove function than milk protein,
soy flour or fish protein concentrate (Guilhermet et al., 1973) and
there is some suggestion that fish protein concentrate may pass into
the rumen and cause bloat (Makdani et al., 1971b).

Due to the esophageal groove, the first enzymatic action on
dietary protein occurs in the abomasum. Pepsinogen, prorennin, and
HCl are the main digestive secretion of the abomasum (Huber, 1969).
Pepsinogen is changed to active enzyme in one of two ways. As HCl
mixes with the precursors, the pH falls below 5.0 and activation is
initiated. In addition, small amounts of pepsin act autocatalytically.
The result is that several peptides are cleaved from the pepsinogen
moleculas to produce the enzyme with pH optima varying between 1.8 and
3.5 (Sanford, 1982). Cholinergic reflexes stimulate abomasal
hydrochloric acid secretion directly by acting on parietal cells,
or indirectly by facilitating gastrin secretion and potentiating

its effect on parietal cells (Debas et al., 1974). The peptic chief

cells appear to respond primarily to direct Cholinergic neural
stimulation, although gastrin was also implicated (Gregory, 1974).

Coagulating activity of the abomasal mucosa exists in the
ruminant fetus (Kirton et al., 1971). Most of this action is due to
rennin for which the general proteolytic activity is lower than of
pepsin (Thivend et al., 1980). Gastric secretions evolve with the
age of the calf and the quantity of milk ingested. In the preruminant
calf fitted with a gastric pouch, the daily quantities of gastric
juice collected increased up to the fifth or seventh week, then
decreased until week 32. Rennin activity decreases according to age,
while pepsin tends to increase slightly (Thivend et al., 1980;
Henschel et al., l96la,b).- Abomasal protease production markedly
increases immediately after feeding but then decreases to below
prefeeding levels (Ash, 1964).

Gastric secretions measured as the quantity of acid passing
out of the abomasum of the preruminant calf, doubled between days 7
and 24 and tripled between days 24 and 63, but amounts of Na+, K+ and
C1- did not increase significantly (Roy and Stobo, 1975). In young
preruminant calves fitted with a gastric pouch however, large cyclic
variations were noted between the second and thirty-second week for
acid secretion as well as for the output of Na+, K+ and Cl- without
Showing large changes with age (Thivend et al., 1980). The origin
and the processing of proteins greatly affect gastric secretion.
Acid secretion decreased when milk protein was replaced by soybean
protein, and increased with fish protein (Roy and Stobo, 1975;

Williams et al., 1976). Digesta from calves given diets with "mildly"

preheated spray-dried skimrmilk powder (MHM) was more acid 1 to 3 h
after feeding than digesta from calves given diet with "severely"
preheated spray-dried skimrmilk powder (SHM). There was also a
tendency for a greater output of acid by the pouches when calves

were given diet MHM (Williams et al., 1976). Tagari and Roy (1969)
concluded from a study of pyloric outflow, that MHM probably stimulated
greater acid secretion than SHM. From measurements of Cl- minus Na+
in the duodenal outflow, Ternouth et a1. (1974), concluded that there
was about 11% greater acid secretion with MHM. Soy flour was a less
effective stimulant to acid secretion than fish protein concentrate

or MHM (Williams et al., 1976). This cannot be explained by any great
difference in the ratio undigested:digested protein in the duodenal
fluid (Termouth et al., 1975) but it may result from differences in
the products of protein degradation (Williams et al., 1976). Hill
(1968), however, pointed out that there is no direct evidence available
on dietary factors which stimulate gastrin production and release in
ruminants.

At weaning, rennin activity in the calf and the lamb decreased
while the pepsin activity remained nearly constant (Thivend et al.,
1980), or increased slightly (Guilloteau et al., 1983). This change
was partially reversible. When animals were given a liquid feed
containing casein, the rennin activity increased again, however,
without reaching the preweaning level and pepsin activity was not
affected (Garnet et al., 1977). The amount of rennin secreted
decreased with the casein content of the milk (Garnot et al., 1977).

After weaning pepsin activity is predominant, but rennin is still

present (Thivend et al., 1980). Hydrochloric acid secretion is
probably very low at birth but increases rapidly (Thivend et al.,
1980). Abomasal parietal cell development in the lamb is great during
the first 3 days after birth (Roy and Stobo, 1975). The pH of abomasal
content is 5-8 before the first drinking but drops to 3.0 by 2 days
(Thivend et al., 1980). Protease and acid output are related to diet.
Acid production was increased by presence of milk in the abomasum

(Ash, 1964).

Development of a firm abomasal clot by milk or milk replacer
has a useful physiological function (Frantzen et al., 1971; Roy and
Stobo, 1975; Tagari and Roy, 1969; Thivend et al., 1979) by improving
protein and fat digestion through prolonging retention time in the
abomasum. Clots help digestion by releasing the nutrients more slowly
into the small intestine where digestive enzymes can act more effec-
tively. A firm curd prevents excessive quantities of undigested
protein from reaching the small intestine (Roy and Stobo, 1975;
Thivend et al., 1979) and is particularly important in calves less
than 3-4 weeks of age, because their digestive system has not fully
developed (Thivend et al., 1979).

Attempts to substitute vegetable proteins for milk proteins
in liquid diets have usually resulted in poorer calf performance
(Radostits and Bell, 1970). This has been attributed, among other
factors, to the lack of a normal coagulum in the abomasum (Roy et al.,
1977). A strong curd formation may also influence fat digestion since
fat globules are enmeshed in the abomasal clot (Hill et al., 1970;

Ternouth et al., 1980). A longer retention time in the abomasum would

allow greater opportunity for fat hydrolysis by pregastric esterase
(Radostits and Bell, 1970; Ternouth et al., 1980). Lister and Emmons
(1976) suggest that coagulation appears to be a requirement for young
calves less than 3 weeks of age fed a diet based on skim milk but not
for older calves.

Other workers have suggested that curd formation in the abomasmm
is not important for normal growth and health of calves (Owen and Brown,
1958; Netke et al., 1962). Owen and Brown (1958) reported that calf
growth was not adversely affected when they added citrate to whole milk
to prevent clotting. Netke et a1. (1962) were unable to show any
effect of low or high milk pH, which was assumed to reduce curd, on
calf health and weight gains.

Jenkins and Emmons (1982) suggest that abomasal chymosin-casein
curd formation may provide a beneficial physiological function in
calves fed whole milk and that coagulation may not be useful for milk
replacers containing a mixture of skimrmilk powder and soluble, poor
quality protein when it promotes a different absorption pattern for
essential amino acids.

Factors which may increase curd formation are: a lower pH of
the skimrmilk (over a range of 5.6-6.6), higher concentration of
skimrmilk solids (over a range of 5-20%), higher concentration of
rennin, lower temperatures of heat treatment of skimrmilk prior to
spray drying, and higher temperature of coagulation, 37 vs. 30°C
(Emmons and Lister, 1976). Defatted rapessed flour (4% wt/wt of
reconstituted lowhheat skimrmilk) has little effect on curd firmness

whereas whey powder (4%) and fish protein concentrate (2%) decreased

gel strength of the reconstituted skimrmilk by approximately 30%.
Soybean meal (4%) and soy protein isolate (2%) markedly reduced curd

firmness; addition of CaCl (0.1-0.4%) restored coagulability and curd

2

firmness. However, addition of CaCl does not restore gel firmness in

2
reconstituted, severely heated skimrmilk powder as occurs with a
low-temperature product. Addition of fat to skim-milk containing

15 or 20% total solids, followed by homogenization, has little effect
on curd firmness at pH 6.1. Fat addition, however, decreases curd
firmness of skimemilk containing 10% total solids and nearly prevents
coagulation in skimvmilk containing 5% total solids (Emmons et al.,
1976). In vitro substitution of skim-milk powder in calf milk replacer
with acid-precipitated casein and whey results in extended coagulation
time with rennin (pH 6.1, 39°C) and weaker curd strength (Jenkins,
1982). Replacement of casein by soya flour or fish-protein concentrate
impairs curd formation in the abomasum, and in comparison with milk
protein, both cause a reduction in rennin and pepsin secretion
(Williams et al., 1976).

Abomasal contents have a pH of l to 2 before feeding and
consist of a fairly clear, slightly viscous fluid containing small
milk clots. During feeding the milk rapidly clots as it enters the
abomasum (Hill, 1968). The acidity of abomasal contents decreases
(pH 6.0) immediately after feeding (Mylrea, 1966a); but as acid
secretion increases, the pH slowly decreases and reaches pre-feeding
values in about 5 hours (Porter, 1969). By this time most of the whey

fluids have left the abomasum and the pH of abomasal contents is

10

low enough for dissolving of the casein clot by action of pepsin
(Mylrea, 1966a; Ternouth et al., 1974).

In the abomasum, milk protein clots through action of rennin
and pepsin which separates milk into a casein clot and whey. The whey
appears in the duodenum within 5 minutes after feeding, but the casein
clot is slowly degraded and its products are subsequently discharged
into the duodenum (Mylrea, 1966a). Pepsin has only one-third the
milk-clotting activity of rennin at near neutral pH but over 20 times
the proteolytic activity at a lower pH (Raymond et al., 1973). The
optimum pH for clotting by rennin is 6.5, whereas the optimum pH for
proteolytic activity is 4.0 for rennin and 2.0 for pepsin (Tagari and
Roy, 1969). There is little difference between results with pepsin
and rennin for the "in vitro" digestion of raw milk (Henschel et al.,
1961b). Both enzymes have similar amino acid sequences (Pedersen and
Foltmann, 1973), but differ drastically in their activity on ribo-
nuclease (RN) as substract. Pepsin inactivates RN and rennin does
not (Bang-Jensen et al., 1964).

The movement of digesta from the abomasum of a calf fed whole
milk is a slow, well-controlled process (Ash, 1964; Mylrea, 1966a).
The rate of flow of digesta is more rapid immediately after feeding,
reaches a peak during the first hour and decreases progressively with
time. However a considerable flow continues for many hours (Ash,
1964). With increasing time, the digesta contains a greater proportion
of endogenous origin, but certain dietary constituents such as
nitrogeneous components and fat continue to be found for many hours

(Mylrea, 1966b; Toullec and Mathieu, 1973). Ternouth et a1. (1974)

11

suggested that the major factor regulating abomasal emptying is the
tension of the abomasal wall and that the enteric inhibition of
abomasal emptying is relatively unimportant for 12 hours postprandiaLhn
Smith and Sissons (1975) found that duodenal outflow of calves receiv-
ing milk protein or soybean products for one or two occasions
(unsensitized calves) was different from calves receiving certain
soybean products, for a number of these feedings (sensitized calves).
For unsensitized calves, the rates of flow of total digesta from the
abomasum after giving synthetic milk prepared from different protein
sources were similar to those after cow's milk was given. Total
digesta flow was greater in the first few hours after a feed
consisting of a mineral solution was given than after cow's milk
was given. For sensitized calves, rates of flow of total digesta
from the abomasum were greatly affected by the nature of the protein
source used in the diet. Soybean flour (heated or unheated) generally
caused inhibition of flow for some hours after feeding; soybean protein
isolate (isoelectric) had a similar but lesser effect; whereas soybean
concentrate (prepared by alcohol extraction of a soybean flour) and
milk protein had little or no effect.

In contrast to Smith and Sissons (1975) increased outflow of
undigested protein during the first hour after feeding was observed
in calves fed "severely“ heat-treated skimemilk powder (Tagari and
Roy, 1969), or when milk protein was replaced by soybean flour (Colvin
et al., 1969), fish protein concentrate (Ternouth et al., 1975) or

whey powder (Gorrill and Nicholson, 1972a).

12

In spite of the conclusion of Guilloteau et a1. (1979) that
suppressing transit of digesta into the abomasum (by infusion into
the duodenum) and accelerating the rate of passage have an adverse
effect on nitrogen and liquid digestibilities, the data previously
mentioned and the observation by Christison and Bell (1976) that a
more digestible pea protein left the abomasum faster than a poorly
digested pea product suggests that the rate of passage of crude protein
through the abomasum was not a major factor in determining the crude
protein digestibility. Smith and Sissons (1975) suggest that an
abomasal inhibition of outflow is a sign of more general disorders
such as an induced change in the duodenum perhaps resulting from a
gastrointestinal allergy.

After being partially digested by gastric enzymes in the
abomasum, dietary protein goes to small intestine where hydrolysis
continues by action of the trypsin, chymotrypsin and carboxypeptidase
present in the pancreatic juice, and by proteases present in intestinal
mucosa cells (Huber, 1969; Porter, 1969; Radostits and Bell, 1970).

Pancreatic flow increases with age, but in very young calves
it increases during feeding and decreases 1-2 hours after feeding.

By four months of age the flow becomes more constant, approaching the
pattern observed in mature sheep (McCormick and Stewart, 1967). Huber
et al. (1961b) found that the levels of pancreatic proteases were low
in newborn calves but increased three-fold by 2 weeks of age with
little change to 6 weeks. There doesn't appear to be a marked increase
in the activity of these enzymes with age but total amounts available

for digestion increase markedly because of higher pancreatic flow rates

13

(Gorrill and Thomas, 1965; Gorrill et al., 1967). In contrast,
maximum pancreatic enzyme activity occurred only in adult cattle
(Clary et al., 1969; Track and Bokermann, 1973). Pelletier and
Dunnigan (1983) showed that glucocorticoid administration to young
calves has beneficial effect upon the development of the pancreas,
but could have a detrimental effect on growth of the animal.

The proteolytic enzymes in the pancreatic juice are released
as inactive precursors. Trypsinogen changes spontaneously to the
active form in solution, but this change may be accelerated in two
ways. First, enterokinase, secreted into the intestinal contents,
resists proteolytic digestion and catalyses the conversion of
trypsinogen to trypsin. Second, activated trypsin converts more
precursors into the active form. Trypsin hydrolyses peptide bonds
within the protein molecule (endopolypeptidase), particularly those
in which the carboxyl groups are provided by an amino acid with a
positively-charged side chain such as lysine or arginine. Chymo-
trypsinogen is activated to chymotrypsin by trypsin. Chymotrypsin
acts preferentially on peptide bonds in which the carboxyl groups
are provided by tyrosine or phenylalanine. Carboxypeptidase is also
changed from its zymogen by action of trypsin that cleaves animo acids
with the free carboxyl groups from the end of peptide chains (Sanford,
1982).

After proteolytic enzymes from gastric and pancreatic juices
as well as some derived from sloughed epithelial cells have exerted
their effects on dietary proteins, a mixture of free amino acids and

small peptides remains. Two distinct groups of enzymes are thought

14

to be involved in the subsequent peptide hydrolysis; one is associated
with the brush border membrane, while the other is located in the
cytoplasm of the intestine epithelial cells (Sanford, 1982).

Large increases of trypsin and chymotrypsin activities occur
in digesta of calves shortly after feeding (Gorrill et al., 1967;
McCormick and Stewart, 1967; Gorrill and Nicholson, 1971; Ternouth
et al., 1975). However, this large output of enzymes from the pancreas
does not coincide with the main outflow of total nitrogen and lipids
from the abomasum which occur 5 to 10 hours after feeding (Ternouth
et al., 1975). The increase in pancreatic flow (but not enzyme
concentration) 6 to 12 hours after feeding was due to stimulation
by secretin (Ternouth et al., 1976). Gastrin has also been shown to
stimulate both flow and enzymatic activities of pancreatic fluid
(Henriksen and WOrning, 1969).

Pancreatic exocrine secretion is controlled by a neural and
hormonal mechanism (Thomas, 1967; Harper, 1972). The quantity of
enzymes secreted by the pancreas decreases when these enzymes are
prevented from entering the duodenum (Taylor, 1962). The presence of
trypsin into the intestine may have a feedback regulatory mechanism
on pancreatic secretion through modulation of the release of secretin
(Davicco et al., 1979). McCormick and Stewart (1967) suggested that
the increase in pancreatic flow at feeding time may be a cephalic
effect, but it doesn't appear to be the gastric induced phase.

Diet may affect pancreatic secretion. When the calf is given
solid feed which is digested in the rumen, daily pancreatic secretion

(11.3-13.5 ml/kg liveweight) was lower than when it was fed milk

15

(19.7 ml/kg liveweight) (Ternouth et al., 1977). However, trypsin
activity, per unit pancreatic weight is greater in the ruminant than
the preruminant (Shingoethe et al., 1970).

Calves fed milk replacer containing soybean flour with a high
content of trypsin inhibitor showed a reduction of trypsin and
chymotrypsin activities of the pancreas and intestinal contents,
as well as lower in_xit£g_protein digestion incubation (Gorrill and
Thomas, 1967). Calves fed an all-milk diet secreted a significantly
greater quantity of pancreatic juice and higher concentrations of
trypsin and chymotrypsin than those receiving a high soybean-protein
diet (Gorrill et al., 1967; Gorrill and Nicholson, 1971). Roy (1969)
suggested that the diarrhea in calves fed soybean protein with a high
level of trypsin inhibitor could be due to protein and peptide accumu-
lation in the large intestine and subsequent fermentation by
microorganisms. Accumulation of undigested protein in the lower
intestine of animals fed soybean trypsin inhibitor was observed in
calves (Gorrill and Nicholson, 1971), chicks (Coates et al., 1970)
and rats (Carroll et al., 1952).

Carbohydrate Digestion in
Preruminant Calves

 

 

Whereas monosaccharides can be absorbed and passed into the
blood stream intact, di- and poly-saccharides require hydrolysis to
monosaccharides before effective utilization can take place. Siddons
et a1. (1969) found that glucose, galactose and xylose were absorbed
from the intestines of preruminant calves of up to 106 days of age,

and each caused large increases in concentrations of blood reducing

l6

sugars. Responses to glucose and galactose were greater with 50-day-ohi
than with younger calves, and at this age the maximum increases due to
glucose were greater than galactose, although increases were similar
with younger calves. When glucose was offered the entire increase was
in blood glucose, but galactose caused only a small increase in blood
glucose, and feed did not affect glucose in blood. Fructose caused

no increases in blood reducing sugars of lO-day-old calves, but small
increases were found in 30- and 50-day-old animals. Fructose feeding
also resulted in severe scouring in young calves.

Lactose caused marked increases in the levels of both blood
reducing sugars and blood glucose when fed to fasted calves and there
was little difference in the response of calves of different ages up to
50 days (Dollar and Porter, 1957; Huber et al., 1961). Maltose caused
only small increases in reducing sugar levels, though the response
increased slightly with age (Porter, 1969). Sucrose and starch caused
no increase in the level of blood reducing sugar of preruminant calves
(Porter, 1969; Siddons et al., 1969).

At birth the calf has large quantities of intestinal lactase
as demonstrated by Dollar and Porter (1957) and Huber et al. (1961b).
With advancing age, lactase levels gradually decline (Huber et al.,
1961b), which may be a reflection of the animal's decreasing dependence
on milk or of a greater proportion of milk entering the rumen which is
subsequently digested by rumen microflora (Radostits and Bell, 1970).
The intestinal lactase levels increased significantly when calves were
fed whole milk with increasing amounts of added lactose (Huber et al.,

1964). Adaptation to lactose was also strongly indicated by efficient

l7

gains and high blood sugar responses in yearling steers after being
changed from a hay-grain to a suckled liquid diet high in lactose
(Huber et al., 1967). These data suggest that postruminal utilization
of lactose is highly regenerative in the bovine.

Lactase is a beta-D-galactosidase found in the brush border
of the intestinal mucosa which hydrolyzes lactose into D—glucose and
D—galactose at an optimum pH range of 5.5 to 6.0 (Radostits and Bell,
1970). Highest lactase is found in the duodenal part of the small
intestine, and activity decreased distally from the duodenum (Huber
et al., 1961b). No lactase was found in the colon or in pancreatic
secretions (Heilskov, 1951a,b). A relative deficiency of lactase would
result in excessive quantities of lactose in the small intestine which,
in turn might result in fermentative diarrhea (Huber et al., 1964;
Weijers and van de Kamer, 1965).

At birth the calf is unable to utilize maltose, but maltase
activity was observed by seven weeks of age (Dollar and Porter, 1957).
very young calves show little evidence of maltase activity and can
utilize maltose only if given supplementary maltase (Dollar and Porter,
1957). However, maltose utilization, as shown by increase in reducing
sugar activity after feeding maltose, increased markedly between 8 and
50 days of age (Huber et al., 1961b). It has also been demonstrated
that young calves are unable to utilize dietary sucrose when fed in
milk or milk replacers (Okamoto et al., 1959; Huber et al., l96la,b;
Siddons et al., 1969; Coombe and Siddons, 1973).

Ruminants secrete no salivary amylase (Kay, 1966). Pancreatic

amylase is low at birth (Huber et al., 1961a) and compared to other

18

species, is still poorly developed at nine months of age (Larsen
et al., 1956), but large increases were reported by Ternouth et a1.
(1971) from 24 to 63 days in Ayrshire calves with a slower rate of
increase in Friesians.

Digestion trials have indicated a measurable disappearance of
starch fed to young calves (Shaw et al., 1918; Maynard and Norris,
1923) however only a low increase in blood reducing sugar occurred
after feeding starch (Huber et al., 1961b). Liang et a1. (1967)
showed that milk-fed calves absorbed and utilized volatile fatty acid
placed into the cecum or colon suggesting that preruminant calves may
be able to benefit from some of the undigested dietary starch as an
energy source. Growth studies have corroborated digestibility data
to indicate poor utilization of starch (Flipse et al., 1950; Dollar
and Porter, 1957; Huber et al., 1967; Huber et al., 1968).

A small increase in starch digestibility with age has been
reported (Shaw et al., 1918; Noller et al., 1956; Huber et al., 1968).
However there was no increase in ability of yearling steers to digest
starch after being adapted to a liquid ration high in starch (Huber
et al., 1967), nor was any adaptation to maize starch shown when
included in liquid ration for 10- to l4—week-old calves (Raven and
Robison, 1965).

At 6 weeks of age, about 50% of dietary starch was digested
and absorbed from the small intestine (Coombe and Smith, 1972).
Extensive studies in France have shown that inclusion of 75 g starch
or dextrins/kg in liquid diets from 13 days of age markedly depressed

growth. Raw starch or poorly soluble dextrins caused constipation

19

whereas hydrothermically treated starches or soluble dextrins caused
diarrhea (Mathieu and Thivend, 1968; Mathieu et al., 1970).

Sucrase is absent in the intestinal mucose of ruminants (Dollar
and Porter, 1957; Huber et al., 1961a). Consequently, low digesti-
bilities of sucrose (Huber et al., 1961a; Henschel et al., 1963;
Morrill et al., 1965), severe diarrhea upon ingestion of sizeable
quantities of sucrose (Netke et al., 1960), and no increment in blood
reducing sugars after feeding sucrose solution have been reported
(Dollar et al., 1957; Dollar et al., 1959; Huber et al., 1961a,b).

On the other hand, an active fermentation of sucrose by microorganisms
in the lower digestive tract has been reported (Henschel et al., 1963;
Morrill et al., 1965).

Undergraded or partially degraded carbohydrates which reach
the large intestine and cecum are substrates for microbial fermentation
resulting in organic acid production (Norris et al., 1925). Organic
acid concentration of about 10 meg/100 ml have been reported in the
lower digestive tract of calves on milk plus high-lactose or hay-grain
rations (Huber and Moore, 1964). This concentration is as high as
those reported in the rumen. Calves which received only milk exhibited
concentrations about 50% as high as those on high lactose or on hay
plus grain diets (Huber and Moore, 1964). Liang et a1. (1967) showed
efficient absorption of acetate, propionate, and butyrate from the
small and large intestines of calves with 52 to 87% of the 14C

appearing in the expired C0 during the first day.

2

20

Soybean Proteins for Milk Replacers

 

The soybean is one of the few vegetable materials that contains
protein having a reasonably well-balanced amino acid composition
(Porter, 1969). However, raw soybeans contain a heat-labile trypsin
inhibitor and other factors causing a depression in food intake, poor
growth, increased secretion of pancreatic enzyme and hypertrophy of
the pancreas in young rats and chicks (Michelsen and Yang, 1966;
Sambeth et al., 1967).

Four main soybean products have been used in milk replacers
for calves: soybean meal, soybean flour, soybean protein concentrate
and soybean protein isolate. They average 45, 60, 70 and 90% crude
protein and 45, 35, 25 and 5% carbohydrate, respectively. A summary
of calf performance when calves received the different soybean protein
sources in milk replacers can be seen in Table l.

The use of soybean products to feed young calves has resulted
in poorer performance than milk (Williams and Knodt, 1951; Kakade
et al., 1974; Thompson et al., 1974). Reduced body weight gain and
decreased dry matter, crude protein, fat, and ash digestibility have
been linked to increases in the soybean products in milk replacers
for calves (Nitsan et al., 1971, 1972; Pejic and Kay, 1979). Negative
results have been related to the presence of soybean trypsin inhibitor
(SBTI) (Gorrill et al., 1967; Gorrill and Thomas, 1967), residual
carbohydrates such as neutral arabinogalactans, acidic polyssacharides
and arabinans (Kellor, 1974), and the antigenic globulins glycinin

and beta-conglycinin (Sissons and Smith, 1976; Kilshaw and Sissons,

21

 

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22

 

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24

1979a; Kilshaw and Slade, 1980), as well as to unknown factor(s)
(Gertler and Nitsan, 1970; Nitsan et al., 1971).

Gorrill and Thomas (1967) found poor growth, but no hypertrophy
of the pancreas in calves given a methionine-supplemented diet in which
soybean flour containing trypsin inhibitor supplied 60% of the protein.
The pancreatic juice and intestinal contents of calves contained less
trypsin and chymotrypsin activities than those of calves given milk
or a soybean flour having a very low trypsin inhibitor. The deleterious
effects of the presence of SBTI were confirmed by Colvin and Ramsey
(1968) although their major finding was that the nutritive value of
trypsin inhibitor-free soybean flour was markedly improved by treatment
with acid at pH 4 for 5 h at 37°C. Calves given the acid-treated
soybean flour grew at nearly twice the rate of those receiving the
untreated material. Kakade et al. (1976) did not find differences in
weight or enzymatic activities of pancreas in calves due to SBTI.

They concluded that SBTI plays a minor role, if any, in calf nutrition.
The reduction in pancreatic secretions in calves fed SBTI contrasts to
studies with chicks and rats in which extracts from raw soybeans
induced pancreatic hypertrophy and hypersecretion of digestive enzymes
(Haines and Lyman, 1961; Garlich and Nescheim, 1966; Michelsen and
Yang, 1966). Response of swine pancreas to raw soybeans is similar

to that observed in calves (Hooks et al., 1965). Diets containing
soybean flour have also been reported to reduce gastric acid secretion
(Williams et al., 1976) and retention time of protein in the abomasum
(Colvin et al., 1969; Smith et al., 1970) with a resultant decrease in

proteolysis. Attempts to improve digestibility of isolated soybean

25

protein used in milk replacers by pepsin and pancreatin supplementation
had a detrimental effect in calf performance (Jenkins, 1981). Supple-
mentation with these enzymes, separately or together, also reduced
apparent digestibility of dry matter, and nitrogen, but had no effect
on feed intakes (Jenkins, 1981). In_yit£g studies have shown that
both pepsin and the pancreatic proteases have much better hydrolytic
activity on milk protein than on soybean protein (Jenkins et al.,

1980; Jenkins, 1981).

Willard and Ramsey (1972) suggested that the further removal
of the small amounts of trypsin inhibitor in heated soybean flour by
acid or alkali treatment improves nutritional value, but this finding
was not supported by Sissons and Smith (1976).

An inactive form of trypsin inhibitor in fully-cooked soy flour
that is converted to an active form in the pH range of 7 to 9 was
reported by Ramsey and Willard (1975). This inhibitor can be destroyed
by heating the soy flour in water, but the extent of destruction
appears dependent on the concentration of flour in the water. The
presence of trypsin inhibitor in fully-cooked soy flour is offered
as a possible explanation for the observation that newborn calves
often do not perform well on milk replacers containing large quantities
of this product.

Acid or alkali treatment of toasted soybean flour (Colvin and
Ramsey, 1968, 1969; Colvin et al., 1969) or extraction with alcohol
(Nitsan et al., 1972; Smith and Sissons, 1975) has improved its
quality. Thermo-alkali treatment with lower temperatures inactivates

SBTI more effectively than thermo-acid treatment (wallace et al., 1971).

26

The presence of complex carbohydrates in soybean products,
mainly in soybean meal and soybean flour which have 45 and 35% carbo-
hydrates, may explain some of the poor results reported when these
products are fed to young calves. Roy et a1. (1977) concluded that
feeding of soybean flour may have detrimental effects due to the
presence of trypsin inhibitor, haemagglutimins, a large content of
oligosaccharides (which probably cannot be utilized by the calf)
and phytin.

Roy et a1. (1977) also observed a lower Ca absorption in calves
fed milk replacers containing soybean flour than all milk. This was
attributed to the phytin in soybean flour, which accounts for 70% of
the total phosphorous, and is not only unavailable for simple-stomached
animals but interferes with the absorption of calcium, iron and zinc
(Taylor, 1965; O'Dell, 1969; Thompson and Erdman, 1984). Disappearance
from the gut of considerable carbohydrate from soy protein sources
(Nitsan et al., 1971, 1972; Kakade et al., 1976) is presumably due to
intestinal fermentation. Feeding of high chlorotetracycline to depress
intestinal fermentation did not improve growth in calves fed untreated
soybean flour (Colvin and Ramsey, 1969).

Enzymatic pre-digestion of soybean flour did not stimulate
growth, even though the carbohydrate fraction underwent extensive
degradation (Colvin and Ramsey, 1968). Removal of the water-soluble
carbohydrates from soybean flour did not improve growth and addition
of the water-soluble carbohydrates to a replacer containing soybean

flour did not depress growth (Sudweeks and Ramsey, 1972).

27

Smith and Wynn (1971) reported large amounts of hemaglutinates
in calf blood, when milk protein was completely replaced by soybean
flour or when successive feedings of soybean flour was interpersed
with feedings of normal milk diets. Smith and Sissons (1975) found
that soybean flour and isolated soybean protein caused inhibition of
the digesta flow from the abomasum for a few hours after feeding.

They suggested this inhibition was a sign of more general disorders
caused by a factor entering the duodenum which induced a change in the
way the calf responded, probably as the result of a gastrointestinal
allergy. Calves given soybean flour showed high titres of serum
antibodies to an antigen from soybean flour.

Preruminant calves fed heated soybean flour produced high
titres of serum IgG and IgE antibodies specific for soybean protein
glycinin and beta-conglycinin (Kilshaw and Sissons, l979a,b).

Barratt et a1. (1978) reported a complement-fixing IgGl preciptin

as the predominant antibody in calves fed alcohol-extracted soybean
protein. The soybean antigen was shown resistent to proteolysis and,
to a lesser degree, to the microbial action of rumen fluid. No
evidence of tolerance was seen and previously sensitized calves
responded with marked increases in antibody levels. Biopsy studies
showed morphological disturbances to the villi and lamina propria of
the intestine. Benzyl isothiocyanate has also been identified as a
prominent allergen in soybeans. Calves fed whole milk to which 90 mg
benzyl isothiocyanate was added showed poor growth rates and persistent
diarrhea, identical to those fed milk replacer containing soybean flour

(Gardner et al., 1982).

28

Gradual deterioration in villus integrity was reported by
Seegraber and Morrill (l982a,b) in calves fed soybean proteins.
Abnormalities included an absence of villi, while those remaining
were short, blunted and convoluted. Deterioration of villi tended
to be reversed with a return toward normal size and shape when the
diet was changed to milk. These data were supported by Kilshaw and
Slade (1982) who reported partial atrophy of villi and crypt enlonga-
tion in calves given heated soybean flour. The first exposure to
soybean protein caused a slight shortening of villi, but after
successive feedings, animals developed marked mucosal abnormalities
and severe diarrhea. MacDonald and Ferguson (1976) suggested that
a local cell-mediated immunologic reaction may be the cause of villus
atrophy, crypt hyperplasia, and malabsorption of food. Kilshaw and
Slade (1980) showed that successive feeding of heated soybean flour to
preruminant calves caused progressively larger increases in intestinal
permeability and rising titers of serum antibodies (IgG, IgA and IgM)
to soybean proteins. This response was observed in about 50% of the
calves tested.

An essential function of the gastrointestinal mucosa is
exclusion from the circulation of bacteria, toxins and food antigens.
An effective barrier is formed by the interaction of immunologically
specific and non-specific defense mechanisms (Walker, 1976). It is
generally believed that in normal circumstances only trace quantities
of macromolecules pass unchanged from the gut into the blood. A break
in the mucosal barrier might therefore have pathogenic consequences

(walker and Isselbacher, 1974). Inflammatory reactions in the

29

intestinal mucosa can increase the absorption of undegraded protein
(Bloch et al., 1979). This is suggested to occur in food allergies
(Paganelli et al., 1979) and might explain some of the observed
responses of calves to soybeans.

Methionine has been shown to be the most limiting amino acid
in soybean protein for rats, chicks and pigs (Almiquist et al., 1942;
Hays et al., 1959; Berry et al., 1962). Lysine was lower in the
alkali-treated than untreated soybean concentrate (Gorrill, 1970),
and lysine, cysteine and serine were reduced when isolated soybean
protein was mildly treated with .02N NaOH (DeGroot and Slump, 1969).
Gorrill and Nicholson (1969) reported no increase in growth or
nitrogen retention in young calves fed milk replacers containing
70% of the dietary protein from soybean protein concentrate which
was supplemented with methionine (0.1% of dry matter) but Porter and
Hill (1964) showed improved calf performance when methionine was
supplemented to isolated soybean protein, thereby increasing its
content from 1.5 to 2.3 g/100 g of protein.

The maximum level of milk protein substitution by soybean
protein varies with the type of soybean protein source used. Gorrill
and Thomas (1967) reported that 86% replacement of milk protein by
soybean protein concentrate resulted in weight gains similar to that
of calves fed whole milk. Gorrill and Nicholson (1969) concluded that
the soybean protein concentrate could supply up to 70% of the protein
in milk replacer for rearing dairy calves. In contrast, Morrill et a1.
(1971) stated that soybean protein concentrate could successfully

replace 22%, but not 44% of total protein in milk replacers.

3O

Nitsan et a1. (1971) and Nitsan et a1. (1972) concluded that
milk replacers containing soybean protein concentrate up to 88% of the
total protein can be used if a calf starter containing cereal grains
and soybean meal of 16% crude protein is also supplied. Similar
results were reported by Guilhoteau et a1. (1977). Roy et al. (1977)
reported that up to 36% milk protein could be replaced by protein
from a thermo alkali-treated soybean flour without markedly affecting

calf performance.

Other Protein Sources for Milk Replacers

 

Milk is the natural source of protein for the newborn calf.
Proteins of raw milk and of spray-dried milk are of high biological
value and are generally well utilized. Casein is quite satisfactory
as the sole source of protein in synthetic diets for 1-2 week old
calves has resulted in values for percentage nitrogen retention and
apparent nitrogen digestibility of 35 and 86, respectively; compared
values for raw milk of 49 and 91 (Porter, 1969). Problems arise in
heat-treatment of milk if the time-temperature relationship is such
that the whey proteins, including the Ig, are denatured. Such milk
powders have a slow rate of clotting; and instead of forming a firm
curd, a flocculent precipitate is produced (Tagari and Roy, 1969).
Gastric acid production and proteolysis are reduced causing passage
of undigested casein into the duodenum. Pancreatic secretion and
protease outflow are also reduced (Ternouth and Roy, 1973). A lower
over-all digestibility of protein, fat and ash is observed. Such

diets may predispose calves to enteric infection if they have

31

received only marginal passive immunity or are exposed to an adverse
microflora (Roy, 1974).

Fish products have been used to replace part of the milk protein
in milk replacers for calves. Marked variability in nutritional value
was obtained from the different fish species and from the various
processing procedures (Miller, 1956; Morrison and McLaughlan, 1961;
Morrison et al., 1962; Makdani et al., 1971a; Jenkins et al., 1982;
Campos et al., 1982; Huber and Campos, 1982).

Much of the early work using fish meal (Rupel and Wilson, 1962;
Genskow et al., 1968; Wendlandt et al., 1968; Gorrill et al., 1975) or
fish flour (Harshbarger and Gelwicks, 1965; Huber and Slade, 1967;
Williams and Rust, 1968) was unsuccessful because of the low quality
and isolubility of the material.

Dried fish solubles are made of stickwater, an aqueous extract
from cooked fish usually obtained from fish meal plants where fish are
cooked and separated by pressure into an aqueous extract and a fish
pulp (Lassen, 1965). Inclusion of even moderate amounts of spray-dried
fish solubles in milk replacers produced poor growth, low feed
efficiency, and high calf mortalities (Campos et al., l982a,b).

When fish protein concentrate replaced up to 35% of the protein
in calf milk replacer, growth was satisfactory, but depressed gains
resulted from feeding more fish (Huber and Slade, 1967; Genskow et al.,
1968; Makdani et al., 1971a). Proposed causes for the negative results
with fish protein concentrate were low protein digestibility and poor
nitrogen retention (Matre, 1970; Sleiman and Huber, 1971); poor quality

of essential amino acids (Sleiman and Huber, 1971; Roy et al., 1977);

32

vitamin E deficiency (Genskow et al., 1968; Michel et al., 1972);
toxic compounds associated with the solvent (Munro and Morrisson,
1967; Makdani et al., 1971a); aplastic anemia (Picken et al., 1952;
Schultze et al., 1959); and high ash content of the fish protein
concentrate (Gillespie, 1971; Makdani et al., 1971a). Gorrill et a1.
(1975) concluded that isopropanol-extracted fish protein concentrate
could replace up to 62% of the total nitrogen in milk replacers without
having a detrimental effect on calf performance.

Dehulled rapeseed meal was used to supply 30% of the protein
in milk replacers with no significant decrease in calf performance
(Gorrill et al., 1976); while dehulled, low-erucic-acid, low—
glucosinolate, full-fat rapeseed replaced up to 50% of the protein
in milk replacers without significantly affecting lamb performance
(Seoane et al., 1976). Gorrill et al. (1974) concluded that rapeseed
protein concentrate, but not rapeseed flour, could supply at least 25%
of the total nitrogen in lamb milk replacers.

Meat meals were shown to be a poor source of protein in milk
replacers, and resulted in low nitrogen retention and decreased
nutrient utilization. Meat meals contain mainly collagen, which is
approximately 13% hydroxy-proline and largely unavailable to the calf
(Raven, 1972; Polzin et al., 1976). On the other hand, blood meal and
blood flour were of comparable value in milk replacers, resulting in
slightly lower growth than all—milk protein (Brumbaugh and Knodt,
(1952)

Fababean was substituted for up to 25% of the milk protein in

milk replacers (Wittenberg and Ingalls, 1979); alfalfa for up to 50%

33

(Alpan et al., 1979) and crab meal for up to 20% (Patton et al., 1975).

These sources all gave acceptable calf performance.

Summaryiof the Literature Review

 

The literature reviewed has shown that soybean protein may
replace most of milk protein in milk replacers for baby calves.
However, the use of soybean products has resulted in poorer performance
than milk. Reduced body weight gain and decreased dry matter, crude
protein, fat, and ash digestibility have been linked to increased
incorporation of soybean products. Negative results have been related
to the presence of soybean trypsin inhibitor, residual carbohydrates
such as neutral arabino galactans, acidic polyssacharides and arabinans,
soybean antigenic globulins (glycinin and beta-conglycinin), the low
levels of methionine and lysine, as well as to unknown factor(s).

The objective of Experiment 1 was to test digestibility and
absorption of the "modified soybean protein" and related these to calf
performance. In Experiment 2 was detect any alterations of small
intestinal mucosa caused by incorporation of large amounts of soybean

protein in milk replacers were studied.

MATERIAL AND METHODS

qufimam].

 

This experiment was conducted from August 31 to November 9,
1982 with the objective to compare digestibility and absorption of a
"modified soybean protein" and heated soybean flour with milk protein
as protein sources in milk replacers for baby calves.

During a 4 week period twenty-four male Holstein calves (3-4
days of age) were purchased from a commercial dairy farm and trans-
ported to the Michigan State University Dairy Cattle Center (MSUDCC).
The day calves arrived they were identified by an ear tag, weighed,
navels were desinfected with iodine solution and calves were started
on the experimental ration. Also, each calf received an injectable
solution containing 1,000,000 IU of vitamin A, 150,000 10 of vitamin D3,
136 IU of vitamin E and 2 mg of selenium. Based on its body weights
each group of 6 calves was split into 2 blocks, heavy and light, and
calves in each block were randomly allotted to one of the 3 experimental
diets. Except for the digestibility and xylose test periods, calves
were kept indoors in tie stalls bedded with straw.

From 4 to 52 days of age each calf was fed its designated milk
replacer as the only source of nutrients at 8, 9, 10, ll, 12, 12, 12
and 12% of body weight from 1 to 8 weeks, respectively. Solids content

after mixing with warm water (approximately 37°C) was 14%. Replacers

34

35

were prepared just before feeding and fed twice daily (12 hr intervals)
from open pails. Fresh, clean water was available at all times.

The experimental diets all contained 19% crude protein (%DM)
from varying sources. Treatments were:

Treatment MP: 100% milk protein;
Treatment MS: 66% modified soybean protein + 34% milk protein;
Treatment HS: 66% heated soybean flour + 34% milk protein.

Modified soybean protein was obtained by uniformly mixing
defatted soybean flour with a solution of 33.7 parts of 95% ethanol
and 6.3 parts of water and placing the mixture in a closed reactor
where it was heated at 121°C for 30 minutes under a pressure of
1.055 kg/cmz. Afterwards, the flour was sprayed into a drying chamber
where the alcohol and most of the water were evaporated. The material
was then recovered as spray-dried, modified soybean protein.

Ingredient composition of milk replacers is shown in Table 2.
As milk replacers were being fed, a sample was taken from each sack
and composited for laboratory analysis. Milk replacers were analyzed
for dry matter (forced air oven at 70°C), nitrogen (macro-Kjeldahl),
ether extract and ash as described by A.O.A.C. (1980). Chemical
composition of milk replacers is shown in Table 3.

On days 8 and 29, calves were moved to metabolism cages for
collection of feces and urine to determine digestibility of nutrients
and nitrogen retention. Collection periods lasted from 3 to 5 days
depending on calf's capacity to tolerate the collection conditions.
Urine was collected in pans containing 10 ml of a mixture 50% concen-

trated sulfuric acid and 50% water which were placed under metabolism

36

TABLE 2.--Ingredient composition of milk

replacers used in

 

 

 

Experiment 1 (% of spray dried material)a.
Treatment

Ingredient MP MS HS
Nonhydroscopic edible whey 65.58 55.38 55.74
Fat - Milk concentrateb 23.03 22.22 22.45

. c

Casein 10.14 -- --
Modified soybean proteinC -- 21.15 —-
Heated soybean flourC -- -- 20.56
Pre-mix (vit.-min. )6 1.25 1.25 1.25

 

aAll milk replacers contained 250 g/ton neomycin base and

100 g/ton oxitetracycline.
b

40% fat as homogenized white grease which was spray dried

with 60% whey and contained 7% protein.

cCasein - 90% protein; modified soybean protein - 50% protein;

heated soybean four - 50% protein.
d

44 U.S.P. units vit. E/kg; 6.6 mg thiamine/kg; 6.6 mg
riboflavin/kg; 2.6 mg niacin/kg; 13.0 mg d- pantothenic

acid/kg; 0.11 mg biotin/kg; 110 mg ascorbic acid/kg; 6.6 mg
pyridoxine hydrochloride/kg; 0.55 mg folio acid/kg; 0.07 mg

vit. B12; 2,650 mg choline chloride/kg;

iron 100.0 ppm;

copper 10.0 ppm; cobalt 0.1 ppm; zinc 40.0 ppm; manganese

40.0 ppm; iodine 0.25 ppm; and selenium

0.1 ppm.

44,000 U.S.P. units vit. A/kg; 11,000 U.S.P. units vit. D3/kg;

37

TABLE 3.--Chemical composition of milk replacers used in
Experiment 1.

 

 

 

 

 

 

 

Treatment
Measurement MP MS HS
(%)
Dry matter (DM) 96 .92 96 .66 96 . 79
(% of DM)
Crude protein 20.22 19.81 19.25
Ether extract 8.67 8.88 8.49
N-free extract 63.43 63.58 64.53
Ash 7.68 7.73 7.73

 

cages. Feces were collected with light harnesses. A composite sample
of feces for each collection period was made by saving 10% of feces
excreted daily and mixed with that of other days from the same calf.
A composite sample of urine for each collection period was prepared
by saving 1% of the urine excreted daily. Fecal samples were kept at
-20°C until analyzed for dry matter (forced air oven at 70°C), nitrogen
(macro-Kjeldahl), ether extract and ash (as described by A.O.A.C. 1980).
Urine samples were kept at -20°C until analyzed for nitrogen (macro-
Kjeldahl) as described by A.O.A.C. (1980).

Food intake was recorded daily. Calves were weighed on the
first and last day of experiment and at weekly intervals. Fecal
consistency was rated each day for each calf on a scale from 1 to 4

(Larson et al., 1977) with 1 being normal and 4 quite fluid. Rectal

38

temperatures were measured daily just before the morning feeding,
except during collection periods.

A jugular blood sample was taken at 5 hr after feeding to
determine plasma urea nitrogen on 22 and 44 days of the feeding trial.
Plasma was separated by centrifugation at 8,000 g for 20 min and kept
at -20°C until analyzed for urea as described by Fawcet and Scott
(1960).

A xylose disappearance test was performed on day 41 of the
trial to evaluate the rate of xylose clearance from the blood of each
calf. Calves were fasted for 24 hr before administering, by intra-
venous injection, .25 g xylose/kg body weight in 20% water solution.

A xylose absorption test was performed on day 50 of the trial.
Calves were fasted for 24 hr before administering, via nipple bottle,
.5 g xylose/kg body weight in a 10% water solution. For both xylose
tests, jugular blood was sampled just before and 30, 60, 90, 120, 150,
180, 240 and 300 minutes after administration of xylose. Urine also
was collected during the blood sampling period. Plasma and urine were
kept at -20°C until analyzed for xylose by the orcinol/ferric chloride,
spectrophotometric method as described by Seegraber and Morrill (1979).

Two calves randomly chosen from each treatment were sacrificed
by electrocution on the last day of the experiment. After removal of
the entire digestive tract, weights were recorded for rumen, abomasal,
small intestine (divided in three equal length sections), cecal and
large intestinal contents. Samples of contents were kept at -20°C

until analyzed for dry matter, crude protein and ash as described by

39

A.O.A.C. (1980). The pH was also measured for all digestive tract
contents at the time of collection.

Two equally spaced 2.5 cm x 2.5 cm tissue samples were taken
from each of the three sections of small intestine just after the
animal was sacrificed. These samples were taken to the scanning
electron microscopy laboratory and placed in a solution of isotonic
sodium chloride with a pH of 6.0. They were then fixed for 2 hours in
4% glutaraldehyde buffered at pH 7.2 with 0.1 M sodium cacodylate
buffer. Samples were then rinsed twice for 15 minutes in the buffer
alone, dehydrated in a graded ethanol series, and dried at the critical
point in a Balyers Critical Point Drier using C02 as the transitional
gas. Tissue samples were mounted on stubs, coated with gold, and
examined in a Jeol JSM-35C scanning electron microscope using
beam-accelerating voltages of 15 KV at magnifications ranging from
48 to 10,000 X. Selected fields were photographed using a Polaroid
camera. The villi morphology and integrity shown in the micrographs
were evaluated by 5 independent evaluators and classified in a l to 5
scale with 1 being for normal and 5 for quite abnormal or absent villi.

Treatment for illness were recorded daily. Life-Guard (Norden
Laboratories, Inc., Lincoln, NE) was used as an electrolyte and for
body fluid replacement in dehydrated calves. Administration of LS/50
(17.6 mg/kg body weight spectinomycin + 11.0 mg/kg body weight
lincomycin obtained from The Upjohn Company, Kalamazoo, MI) was used
for calves exhibiting body temperatures in excess of 39.5°C for more

than 24 hr.

40

Data were analyzed as a completely randomized block or as a
Split-plot design. Either the Bonferroni t test or designed orthogonal
contrasts were used to compare means, as indicated in the footnotes of
tables. Analysis of variance for all variables was as described by

Gill (1978a,b,c), and these analyses are shown in Table A.1.

Experiment 2

 

This experiment was conducted from April 2 to June 18, 1984
with the objective to detect alterations in small intestinal villi
which might be caused by incorporation of large amounts of soybean
protein into milk replacers for baby calves.

Sixteen male Holstein calves were purchased from the same
commercial dairy farm as those obtained in Experiment 1 and transported
to the MSUDCC. Procedures for receiving these calves were the same as
described for Experiment 1.

Upon arrival at the MSUDCC, calves were fed colostrum obtained
from their dams for 1 feeding and herd colostrum for the subsequent 3
feedings. The colostrum was followed by whole milk for 2 more days.
From 5 to 46 days of age each calf was fed its designated milk replacer
as the only source of nutrients at 8, 9, 10, 11, 12, 12 and 12% body
weight from 1 to 7 weeks, respectively. Solids content of all milk
replacers after mixing with warm water (approximately 37°C) was 14%.
The milk replacers were prepared just before feeding and fed twice
daily (at 12 hr intervals) from an open pail. Fresh, clean water

was available at all times.

41

Initial treatment of these calves differed from those in
Experiment 1 in that they were removed immediately after birth from
their dams in an attempt to avoid any viral infections which might
occur.

The experimental milk replacers contained 23% crude protein
and protein sources were:

Treatment M: 100% milk protein;
Treatment 8: 66% soybean protein concentrate + 34% milk protein.

Ingredient composition of milk replacers is shown in Table 4.
At opening a sample was taken from each sack of milk replacer and used
for compositing prior to laboratory analysis. Replacers were analyzed
for dry matter (forced air oven at 70°C), nitrogen (macro-Kjeldahl),
ether extract and ash as described by A.O.A.C. (1980). Chemical
composition of milk replacers is shown in Table 5.

One-half of the calves were sensitized to soybean protein by
feeding milk replacer S during a 21-day period while the others
received milk replacer M and were not sensitized. After the initial
21-day period, the calves within each group were randomly assigned to
one of the milk replacers for 10 days which was followed by the other
milk replacer for 10 more days. The outline of the experiment is as

follows:

42

TABLE 4.--Ingredient composition of milk replacers used in
Experiment 2 (% of spray dried material).

 

 

 

Treatment

Ingredients M S
Nonhydroscopic edible whey 58.82 52.12
Fat - Milk concentratea 23.00 23.20

. b

Casein 17.40 --
Soybean protein concentratec -- 23.90
Vit. Mineral Premixd 0.78 0.78

 

a40% fat as homogenized white grease, which was spray dried
with 60% whey and contained 7% protein.

b90% protein.

Cprocon 2000 - 67% protein.
d44,000 U.S.P. units vit. A/kg; 11,000 U.S.P. units vit. D3/kg;
44 U.S.P. units vit. E/kg; 6.6 mg thiamine/kg; 6.6 mg
riboflavin/kg; 2.6 mg niacin/kg; 13.0 mg d- pantothenic
acid/kg; 0.11 mg biotin/kg; 110 mg ascorbic acid/kg;

6.6 pyridoxine hydrochloride/kg; 0.55 mg folio acid/kg;

0.07 mg vit. B12; 2,650 mg choline chloride/kg; iron

100.0 ppm; copper 10.0 ppm; cobalt 0.1 ppm; zinc 40.0 ppm;
manganese 40.0 ppm; iodine 0.25 ppm; and selenium 0.1 ppm.

43

TABLE 5.--Chemical composition of milk replacers used in
Experiment 2 .

 

 

 

 

 

 

 

 

 

 

Treatment
Measurement M S
(%)
Dry matter (DM) 96.83 97.30
(% of DM)
Crude protein 23.00 23.06
Ether extract 7.21 7.53
N—free extract 62.90 62.33
Ash 6.89 7.08
P0 P1 P2 Calves
Non Sensitized M S 4
M S M 4
Sensitized M S 4
S S M 4

 

 

 

 

 

PO - Preliminary sensitization period (21 days)
P1 and P2 - Treatment periods (10 days each)

M — Milk replacer with 23% crude protein;
100% as milk protein

S - Milk replacer with 23% crude protein;
66% as soybean protein concentrate
+ 34% as milk protein
During the second week each animal was surgically fitted with

a plastic, Y-shaped, duodenal cannula 1 cm in diameter positioned

about 100 cm posterior to the pyloric sphincter in order to permit

44

biopsy of intestinal mucosa. Initial anesthesia was induced by
halothane gas using a face mask, after which an endotracheal tube
was introduced and anesthesia was maintained with halothane gas.
Calves were placed in left lateral recumbency and the skin of the
right flank was prepared for aseptic surgery. A 10 cm incission was
made 7 cm caudal to the 13th rib. The descending duodenum was isolated
and a purse-string suture was placed into the antimesenteric border.
A 2 cm incision was then made in the intestine such that it could be
closed by tightening the purse-string suture. The cannula was then
inserted into the incision and the suture was drawn tight. A second
purse-string suture was placed over the first so as to invert the cut
edges of the intestine. A small perforation was made in the greater
omentum and the cannula was passed through the hole. A stab incision
was then made through the body wall and skin just caudle to the 13th
rib and the cannula was further passed through to the outer surface
of the body. A plastic flange was then placed over the cannula to
hold it tightly against the abdomen. The incisions in the muscular
layers of the abdomen and the skin were then closed with sutures.
Intestinal mucosa samples were taken by biopsy during the
surgery to fit the cannula and on the last day of each period. Biopsy
samples were taken at the site of surgery and 40 to 50 cm caudal to
the cannula. Tissues were fixed immediately in a 10% phosphate
buffered formalin solution. Villi were stained with 1% new methylene
blue solution and twenty villi were measured from each sample by use
of a dissecting microscope. Measurements of villi were made the same

day or the day following biopsy.

45

Feed intake of calves was recorded daily and body weights on
the first and last days of the experiment, at weekly intervals and on
the first day of each experimental period. Fecal consistency was rated
daily similar to the method described for Experiment 1. Rectal
temperatures were recorded daily just before the morning feeding.

Treatments for illness were recorded daily. Life-Guard (Norden
Laboratories, Inc., Lincoln, NE) was used as an electrolyte and body
fluid replacement in dehydrated calves. All calves were given 1 gm
ampicillim (Omnipen-N, wyeth Laboratories Inc., Philadelphia, PA)
immediately following surgery and twice a day during the next 3 days.
Ampicillim (1 gm per dose) also was given twice daily for 3 days to
all calves exhibiting rectal temperatures higher than 39.7°C for more
than 12 hr. Five hundred mg kanamycin (Kantrim, Veterinary Products
Bristol Laboratories, Syracuse, NY) were added to medication of calves
when the rectal temperatures did not decrease and/or when calves showed
inappetence. Calves which refused to eat were force-fed. Data from
the surgery and PO period were analyzed as a completely randomized
design and those from P1 and P2 periods were analyzed as split-plots,
with treatments as sub-plots in a crossover Latin square design. The
F-test was used to compare means. Analysis of variance for all
variables were as described by Gill (1978a,b,c), and are shown in

Tables A.2 and A.3.

RESULTS AND DISCUSS ION

Experiment 1

Initial body weights were not different between treatments,
but final weights (Table 6) were higher (P<.05) for calves fed milk
protein (MP) than modified soybean protein (MS) or heated soybean flour
(HS). Similar results were observed for body weight gain, gains as a
percent on initial body weight (Table 6) and average daily gains
(Table 7).

A significant (P<.05) interaction of treatment x age was
observed for body weight, total gain and gain as a percent of initial
body weight suggesting that differences between treatment in weight
gains become greater with increased age (Figure l, 2 and 3).

Although soybean products have replaced up to 60 or 70% of the
milk protein in milk replacers for young calves with generally
satisfactory growth, body weight gains were usually lower than those
on only milk protein (Morrill et al., 1971; Nitsan et al., 1972;

Pejic and Kay, 1979; Huber and Campos, 1982; Campos et al., 1982;
Beynen and van Gils, 1983). De Gregorio et a1. (1972) reported no
difference in calf weight gains when milk replacer protein sources
were either modified soybean protein (66% milk protein replacement)
or all milk, but the authors reported higher (P<.05) calf weight gain

for calves fed all milk or modified soybean protein than heated soybean

flour.

46

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Age (days)

Figure 1.--Effect of feeding milk protein, modified soybean
protein, and heated soybean flour on body weight of calves at
different ages. For each age, points with different letters are
different (P<.05) Experiment 1.

50

 

 

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different letters are different (P<.05) Experiment 1.

52

Calves on all treatments lost weight during the 2 first weeks,
but the negative gains were greater (P<.05) for calves fed MS than MP,
and HS was intermediate (Table 7 and Figure 4). This body weight loss
may be related to a poor ability of baby calf's digestive system to
digest and absorb nutrients (Huber, 1969; Porter, 1969; Radostits and
Bell, 1970; Radostits, 1975; Thivend et al., 1980), to the normal
decline in body water content (Houpt, 1977), or to stress when calves
were kept in metabolic cages. Average daily gains were also diminished
during the 5th week when calves again were kept in metabolic cages for
collection of feces and urine (Table 7).

Treatment means for feed intake were higher (P<.025) for MP
than MS or HS (Table 7 and Figure 5) which might be expected because
calves were fed as a percent of body weight.

Feed efficiency (body weight gain/feed intake) was higher
(P<.005) for MP than Ms or HS (Table 7) and the interaction of
treatment x age was significant (P<.005) again showing a widening
of differences between MP and soybean sources as age increased (Figure
6). These results all suggest inferior utilization of soybean than
milk protein and agree with previously published data (Gorrill and
Nicholson, 1969; Morrill et al., 1971; Roy et al., 1977).

Only a few of the calves were able to tolerate for the entire
5 days the metabolism stalls for total collection of feces and urine
during the 2nd week of the trial. Thus, it was not possible to draw
firm conclusions from these data, but trends showing better nutrient
digestibility for MP than for the soybean protein sources were evident

(Table 8).

53

 

a
700. .
I
600- .l
.l
500- .’ b
A 'I.‘.‘. a 0 Pith
.9 400‘ .’ 7"" “f”
/ ° 9
C. , \
Q 300 . .’. //\ \.\ab/
>. 200- .- / b
H /
.3 .
.0 100 - .I/
3 0 °l {
:2 ‘ .’ /
0 _ /
2 100 - a. I ‘
-200. / . ...... MP
5
~300 -: ab/ 6 o —I- MS
-400 AL b —— - —- HS

 

j ‘ I —

(1 8-14 15-21 22—28 29-35 36-42 43-49
Age (days)

Figure 4.--Effect of feeding milk protein (MP), modified
soybean protein (MS), and heated soybean flour (HS) on average
daily gain of calves at different ages. For each age, points
with different letters are different (P<.05) Experiment 1.

54

 

/ .... _ MP
6.0“
‘——*—‘MS
a
5.5} ——-—HS 8 .I.
‘\ /°/ b
/./ ‘\ a/ c
5.0. ‘°
0 . , //
é ./ /\.\b//
04.5- g./ /b\\\‘/
:5 ./' /
E’ ., b . b
.H 4 0' [3’ l/féy
'8 I' "L”
' d
a‘.’ ./// b
3.5 - /} ‘
U
3.0 -
o/
205.
‘L

in.

\T“ 1 1 ‘ fir ' ’-

0 8-14 15-21 22-28 29-35 36-42 43-49
Age (days)

Figure 5.--Effect of feeding milk protein (MP), modified
soybean protein (MS), and heated soybean flour (HS) on feed
intake of calves at different ages. For each age, points with
different letters are different (P<.15) Experiment 1.

55

1.00
d
o/.
I
0.751 . . .l'
."- ‘~¢, e
I. \. . \f...
’/ \\'~. f /7’ e
0.50- J. A.\\‘7° -'
I g /
5' o 25 ‘h g
c . - f
g I
o .’I
'4 I
w OJ ./
W I
m i
'8 0 25 f. I//
a: -- 4 ;/.

I
._._.-.- . MP

 

-o.501 /
b ‘ e— o—0 MS
-o.75‘ / " _ " HS
d
C
-1.00g
\h

 

‘
vr w I T v i,

0 8—14 15-21 22-28 29-35 36-42 43-49
Age (days)

Figure 6.--Effect of feeding milk protein (MP), modified
soybean protein (MS), and heated soybean flour (HS) on feed
efficiency (body weight gain/feed intake) of calves. For each
age, points with different letters are different: a,b,c
(P<.005); d,e (P<.Ol) and f,g (P<.10) Experiment 1.

56

TABLE 8.—-Dry matter (DM), organic matter (OM), crude protein
(CP), ether extract (EB), nitrogen-free extract (NFE)

and ash digestibilities and nitrogen (N) retention

in two-week old calves fed milk protein (MP),

modified soybean protein (MS) or heated soybean

flour (HS) Experiment 1.

 

Treatment (means i SEM)C

 

 

 

 

 

 

variable MP MS HS
No. of calves 3 S

Digestibility (%)

DM 82.32 i 3.46 73.11 t 3.99 77.78 i 3.09

OM 83.41 i 3.50 74.08 i 4.04 78.36 i 3.13

CP 64.13 i 8.26 43.16 i 9.53 49.50 i 7.38

EB 72.31 i 9.81 60.59 i 11.33 74.85 i 8.78

NFE 91.19at 1.55 85.31bi 1.79 87.43a'bi 1.38

Ash 69.22 i 3.63 61.44 i 4.17 70.91 i 3.24
Retention (g/day)

N 14.13 i 6.27 -7.47 i 7.24 4.72 i 5.61

 

a b .
' Means 1n the same row

different (P<.05).

cBonferroni t test.

with different superscripts are

57

The digestibility trial at 5 weeks showed that MP resulted in
greater utilization (P<.05) of dry matter (DM), organic matter (OM),
crude protein (CP), and ether extract (BE) than HS while MS was
intermediate, particularly for digestibility of CP and EE. No
statistical differences between treatment were observed for diges—
tibility of nitrogen-free extract (NFE) or for nitrogen (N) retention
(Table 9).

The grestest reduction in digestibility occurred for CP which
was 22% lower for HS and 13% lower for MS than for MP. There have been
numerous reports showing that soybean proteins are poorly digested by
the young calf during the first few weeks of life (Noller et al., 1956;
Porter, 1969; Morrill et al., 1971; Roy et al., 1977). The poor
digestibility of soybean proteins in young calves has been attributed
to a number of causes, including lack of a normal coagulum in the
abomasum (Roy and Stobo, 1975; Jenkins, 1981), a reduction of
pancreatic secretion of trypsin and chymotrypsin (Gorrill and Thomas,
1967; Ternouth and Roy, 1973), the presence in soybean products of
trypsin inhibitors (Colvin and Ramsey, 1968; Gorrill and Nicholson,
1971), and materials provoking a gastrointestinal allergy (Smith and
Sissons, 1975; Sissons and Smith, 1976). Digestibility of soybean
protein has been improved by acid treatment (Colvin and Ramsey, 1968),
alkali treatment (Gorrill and Nicholson, 1972b) and alcohol treatment
(Sissons et al., 1971; De Gregorio et al., 1982). Heating also has
been reported to improve utilization of soybean products (Nitsan

et al., 1971), but inclusion of pepsin and/or pancreatin in milk

58

TABLE 9.--Dry matter (DM), organic matter (OM), crude protein (CP),
ether extract (EE), nitrogen-free extract (NFE) and ash
digestibilities and nitrogen (N) retention in five-week
old calves fed milk protein (MP), modified soybean
protein (MS) or heated soybean flour (HS) Experiment 1.

 

 

 

 

 

 

 

 

Treatment (means i SEM)d
Variable MP MS HS
No. of calves 8 6 6
Digestibility (%)
DM 89.56 1 1.03a 86.20 1 1.195"b 84.38 1 1.19b
a b b
OM 90.72 1 0.99 87.16 1 1.14 85.30 1 1.14
a b c
CP 82.53 1 1.85 72.07 1 2.14 64.09 1 2.14
EE 94.06 1 0.70a 92.19 1 0.815"b 91.38 1 0.81b
NFE 92.87 1 1.07 91.15 1 1.23 90.83 1 1.23
Ash 75.71 1 1.81 74.56 1 2.09 73.36 1 2.09
Retention (g/day)
N 58.08 1 6.79 39.46 1 7.84 29.47 1 7.84
a,b

'cMeans in the same
different (P<.05).

dBonferroni t test.

row with different superscripts are

59

replacers containing soybean protein did not improve protein diges—
tibility or calf performance (Jenkins, 1981).

Nitrogen retention tended to be 49% lower for HS and 32% lower
for MS than for MP. This reduction of N retention may be explained by
the lower digestibility of soybean than milk protein. Treatment
differences observed for growth and feed efficiencies (Table 6 and 7)
also may be explained by differences in digestibility.

Plasma urea nitrogen (PUN) concentrations showed a tendency
to be lower (P<.10) for MP than for MS or HS on day 23, and lower
(P<.15) for HS than MP or MS on day 44. Moreover, PUN was higher on
day 44 than on day 23 for MP (P<.10) but the reverse was true for HS
(P<.15). No difference between days was observed to MS (Table 10).

The PUN concentrations of this experiment, ranged from 11.4 to
14.0 mg/100 ml, were higher than 5.4 to 6.3 mg/100 ml reported by
Campos (1982), or 8.3 to 11.3 mg/100 ml observed by Foldager (1976);
but were similar to 11.5 mg/100 ml reported by Williams and Smith
(1973); and were lower than 21.2 to 24.6 mg/100 ml reported by Williams
and Smith (1974a,b) or 24.0 to 32.0 mg/100 ml reported by Nitsan et a1.
(1972).

The lower PUN of calves on MP than MS or HS on day 23 was
probably a reflection of the greater uptake of amino acids from blood
to support the more rapid gains. The lower digestibility of soybean
protein and a possible imbalance of amino acid at the tissue level due
to its low methionine content are factors which may also have con-
tributed to the higher pun values (Williams and Smith, 1974a; Eggum,

1970; Roy, 1980). However, on day 44 the growth advantage of MP over

60

TABLE 10.--Effect of feeding milk protein (MP), modified
soybean protein (MS) or heated soybean (HS)
on plasma urea nitrogen (PUN) concentration
of calves at different ages Experiment 1.

 

pun (mg/100 m1)E

 

 

 

Age MP ms HS SEM
23rd day 11.39a'B 13.55b 13.28b'C 11.18
44th day 13.97c'A 13.17d 11.45e'D 11.18
a,b

Means in the same row with different superscripts are
different (P<.10).

c d . - - ‘
' 'eMeans 1n the same row Wlth different superscripts

are different (P<.15).

A'BMeans in the same column with different superscripts

are different (P<.10).

C'DMeans in the same column with different superscripts
are different (P<.10).

EOrthogonal Contrast (MP vs MS + HS; MS vs HS).

HS was even higher, but PUN was lower for calves fed HS than MP. This
may be related to the lower CP digestibility of HS than MP coupled with
increased gains on HS on day 44 compared to day 23.

Absorption and excretion tests of xylose have been used exten-
sively to measure intestinal absorptive capability and renal function
in men (Benson et al., 1957; Butterworth et al., 1959; Hill et al.,
1981), dogs (Hill et al., 197), horses (Roberts, 1974; Bolton et al.,
1976), and calves (Seegraber and Morrill, 1979; Campos and Huber,

1983).

The D(+)xylose absorption test (O-XYL) showed a higher (P<.005)

plasma O-XYL concentration for calves fed MP than soybean protein

61

(Table 11) and treatment differences were greatest at 120 to 180
minutes after oral xylose (Figure 7).

The plasma O-XYL concentrations of this experiment were higher
than those reported by Bolton et al. (1976) for horses, similar to
those of Benson et a1. (1957) and Hill et a1. (1981) for human beings
and Seegraber and Morrill (1979) for calves, but lower than those of
Campos and Huber (1983) for calves.

The curves of plasma O-XYL concentration plotted against time
(Figure 7) showed that peak concentrations occurred 150 minutes after
the oral dose for calves fed MP, but the curve for calves fed soybean
protein were abnormal with no distinguishable peaks (Hill et al., 1970;
Bolton et al., 1976; Seegraber and Morrill, 1979). The curve shown for
calves fed MP indicates superior absorptive capacity of the intestine
compared to calves fed soybean protein (Seegraber and Morrill, 1979)
and corroborates the superior weight gains and nutrient digestibilities
which were observed for the MP treatment (Table 6 to 9).

Cumulative O-XYL excretion determined from the 5 hr of urine
collection taken during O—XYL absorption tests, when expressed as a
percent of xylose, agrees with Seegraber and Morrill (1979) for calves
fed milk protein, but are about twice as high for calves fed soybean
protein (Table 12). The differences between treatments were not
statistically significant, but the tendency of a high XYL excretion
for calves fed soybean protein was associated with greater xylose
disappearance from the blood of soybean-fed calves (Table 12 to 14

and Figure 8 and 9).

62

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.Aoa.vmv ucoummmwo mum mumfluomummdm ucwumMMHU saws :EsHoo 020m 0:» ca mammzm.w

.Amo.vmv ucwanMfio mum mumfisomHGQSm pamHoMMHU nuw3 nasaoo 050m may cw memo:

 

 

v.0

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mm.a Hamm.om mo.mm mH.>N moa.mm ovo.om who.am mm.om vm.mm hm.ma mm
mm.a finmm.mm 0m.vm mw.mm www.mm www.mm mvo.am mv.mm mm.mm vm.oa m:
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mam H oom can omH oma oma om om om ucmfiumoha

manna ucmsummua

 

mmoo Hmuo aux Hmumm moussfiz

 

.H ucoaflummxm m0>amo 0H0 hmnlom on
omumumwcasvm was unmflw3 upon mo mx\qwx m m. «0 mmoo Hmuo Hound AmEmmam HE ooa
\wa 08V coaumuucoocoo Aqwxv mmoahx mammHm momsm>m so Ammv Macaw cmwn>om wmummn

ho .Amzv eamuohm chanson emamaooe .1421 aaouohm sane mo meacoom msoa>mua no uomummun.ss mamas

63

401 {=1

C, a". ~ ‘_‘C.:

\
/" '\,
/' \.
35.. .z' ‘.
/ d \.\
/ d p .‘.‘
Q

I. b \ ' \,
30.. .l. //f‘:>/"j;“\\:f-><f//'d ~4“\ ’ \.\.

Plasma xylose concentration (mg/100 ml)

 

 

i \ 4 ' .
25 d i ‘ \\
.0 \ \.
j
20- 4‘
.II
I ........ MP
15.. /{ .__.“__. MS
/ _ __ _. HS
10. .
‘b
p \
0 30' 60' 90' 120' 150' 180' 240' 300'

Minutes after oral dose

Figure 7.--Effect of feeding milk protein (MP), modified soybean
protein (MS) and heated soybean flour (HS) on calf plasma xylose
concentrations at different times after oral ingestion of .5 g/kg
body weight. For each time points with different letters are
different: a,b (P<.05) and c,d (P<.10) Experiment 1.

64

TABLE 12.-~Percentage of oral or intravenous xylose (XYL)
administered which was excreted into the urine
by calves fed milk protein (MP), modified
soybean protein (MS) or heated soybean flour
(HS) during a 5 hr period after XYL
administration Experiment 1.

 

 

 

 

 

Treatment (means 1 SEM)a'b
Variable MP MS HS
No. of calves 7 8 7
Oral XYL (%) 12.74il.99 9.47:1.86 10.34il.99
No. of calves 7 7 6
IV‘XYL (%) 21.8613.24 20.90:3.24 28.0213.50

 

aMeans in the same row are not significantly different
(P>.20).

bTurkey's test.

65

mamom 90H 0 ca omenowmcmuu nonmamcm 0Ho3 dump 0:9

.AvH manna ommv

.msomsomouwuwn was wonflum> warm

 

 

 

hN.mN 0b.ma hm.mH mw.mm om.m~ vm.om Hw.mm N0.H¢ mw.m¢ mm

No.0m O¢.ma Mb.ma mm.mm oo.vm 0N.Hm ®®.vm mv.mv mo.mv m2

mm.mm mH.mH Hm.om w~.mm vm.mm om.mm mm.mm mm.o¢ mn.m¢ m2

mammfi 00m own owH omH ONH om ow om pcwfiumwua
unmeummus

momoc >H Aux Hmuwm mousse:

.H ucoswnmmxm mm>amo 6H0 mac Hv ou omumumflsflacm
was unmflms upon mo mx\qwx m mm. mo mmoo muonm>0HUGH cm Hmumm AnammHm HE 00H

\wa may coaumuucmosoo Aqwxv omoa>x mammam so Ammv usoam cmmnaom venom: no

.Amzv :Hmuonm amon>0m ©0wMflon .Amzv :kuoum xHflE mo msflpwmm m50w>oum mo uowmwmnl.MH mamas

66

 

 

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.Aom.vmv uc0H0MMflc 0H0 mumfiuomnmmsm ucmuommwc sues :EsHoo 050m 0:» Ga mammzs.m

.Ama.vmv ucmuwmmwo mum mumfisomumm5m uc0H0MMflU :ufi3 :EsHoo 028m may CH mc002m.o

.Amo.vmv ucmhmmmao mum mumfiuomummsm ucmumwmao suds menace 050m map as mammzo.o

.Ammo.vmv uc0H0MMflo mum mumfluomuwmsm uconommwo nufi3 assaoo 050m msu ca mammzn.m
mHo.o «nomv.a obHH.H whmm.a mmm.a noav.a mhv.a £¢Nm.a NHO.H 5mm.a mm
mao.o “novv.a onha.a moom.a mnm.a nmhm.a ~mv.a abmm.a mmm.a mmm.a m2
mao.o Hummv.a oamm.a omom.a mom.H MmNm.H omm.a mmmm.a «mm.a 5mm.a mz

2mm H oom ovm oma oma oma om cm on unwsummwa

 

mcmoa ucwsummua

ammoo >H aux 00006 menses:

 

.H pawsanodxm Amme uaoau
ammnwom condo: Ho .Amzv :Hmuoum cmmnmom wmflMflcos .Amzv :Hmuoum xafifi 00m mmbamo
6H0 >00 av ou voumumficflfibm mm3 unbflms upon mo mx\qwx 0 mm. mo mmoo maocm>muucfl

cm Hmumm AmammHm HE ooa\q»x may meowpmnpcmocoo Aqwxv owedhx mammam mo mod ommu0>dll.va mamma

67

 

 

C

0

W4

4.)

m _

H

:3 - - - .._. -—.

8 \\' 4

g :1 .NT‘°~, a _

o E . . x xx... .. ...-.\

(D O b \'\

U) o ‘s

o H O 4 \ o‘.~

r;\ A I “.~.‘.

x g . b s \No‘.‘.‘ ~

'0 \ a ' ' . _
1.2 C . o

2 1.1 -

0‘ ‘5

§ 0 30' 60' 90' 120' 150' 180' 240'

Minutes after IV dose

Figure 8.--Effect of feeding milk protein (MP), modified soybean
protein (MS), and heated soybean flour (HS) on calf plasma xylose
concentration at different times after IV dose. For each time, points

with different letters are different (P<.05) Experiment 1.

68

 

 

 

5

ca

13

.. 1

g 1.71 _ _u._ MP

0 i .‘_

0 1.6 . \xr.‘ . . MS

8: \‘~H\ ~.

0 E1.5 4 ‘-‘ ‘ —"_ HS

(an) 8 ‘..~.~‘-

3:104 11 \. ‘e‘.‘.~.

5' 21.3 . \;\O‘.‘°~.‘.

‘3 1.2 . \ l\ . “

0‘) \ \,
.3 1.1 . ‘ \
9 h

0 ‘~- I r 1 1 V ‘ “""
O

Q 0 30' 60' 90', 120' 150' 180' 240' 300'

Minutes after IV dose

Figure 9.--Effect of feeding milk protein (MP), modified soybean
protein (MS), and heated soybean flour (HS) on calf plasma xylose
concentration at different times after IV dose. Data presented as
linear regression of log plasma xylose concentration on time
Experiment 1.

69

Plasma xylose concentrations after calves received the intra-
venous dose of xylose (IV-XYL) are in Table 13. These data showed
heterogeneous variance but homogeneity was obtained by transformation
to the log scale. Transformed data are shown in Table 14 and Figure 8.
The plasma IV1XYL concentration was higher (P<.025) for calves fed MP
than MS or HS (Table 14). Linear regression of the plasma IV-XYL
concentration on time (Figure 8) resulted in the following equations:

For treatment MP:

Y = 1.7197006 - 0.0016175x; with correlation

= -0.8534941
For treatment MS:
2 = 1.7190983 - 0.0019063x; with correlation = -O.881336l
For treatment HS:
2 = 1.7312601 - 0.0020887x; with correlation = -O.913337

Origins of the equations were not significantly different but
slopes were. The slope for HS was higher (P<.Ol) than for MP and the
slope for MS tended to be higher (P<.20) than for MP. Slopes for HS
and MS were not significantly different.

When the variation between treatment trends were analyzed by
the partitioned interaction method, plasma IV-XYL clearance was higher
(P<.005) for HS than MS or MP and was higher (P<.005) for MS than MP.

These data suggest greater capacity for clearance of xylose
from the blood of calves fed soybean compared to milk protein with
fastest clearance on the HS diet. Xylose is not normally a constituent
of the blood, although small quantities may be found in urine (White
and Hess, 1956). Xylose clearance from the blood occurs mainly through

renal excretion but some metabolism also occurs. Enzymes have been

70

demonstrated from several bacterial sources by which xylose can be
utilized as an energy source via the pentose phosphate pathway
(Hochster and Watson, 1953). Wyngaarden et a1. (1957) showed that
after an intravenous infusion of D-xylose-l-Cl4 into man, 13.5% of

the radioactive substance was recovered as carbon dioxide in exhaled
air, confirming the observations of Brien et al. (1952) that blood
glucose rises and serum inorganic phosphate falls after the administra-
tion of xylose to human subjects. Hiatt (1957) found incorporation of
about 1% of the administered xylose in the form of glycogen in mouse
liver, while Butterworth (1959) suggested that the liver plays a role
in the removal of xylose from the blood of dogs. Segal et a1. (1957)
found an abrupt lowering of the blood levels of xylose when the plasma
insulin was increased from three to six times the fasting value and
concluded that insulin affects distribution of xylose in body fluids
of man.

The increased IV-XYL clearance from the blood of calves fed
soybean protein compared to milk protein (Figure 9) might be explained
by an increase in xylose metabolism and/or an increase of renal
excretion of xylose. The tendency for a higher percentage of IV-XYL
to be found in urine of calves fed HS diets (Table 12) suggests an
increase in renal excretion. The reason for such an effect is not
clear.

Data of contents from different sections of the gastro-intestinal
tract of 2 calves per treatment slaughtered 5 hr after administration of
a test meal are shown in Table 15. The rumen—reticulum—omasum contents

had a pH ranging from 5.85 to 6.40 with slight tendency to be higher

71

TABLE 15.--Effect of feeding milk protein (MP), modified soybean
protein (MS) or heated soybean flour (HS) to calves
on pH, wet weight, dry matter, organic matter and
crude protein of contents from different sections
of the gastrointestinal tract, also on length of
small intestine and body weighth Experiment 1.

 

 

 

 

 

 

 

Treatments

MP MS HS SEM
No. of calves 2 2 2
Contents from pH
8.8.01 6.40e 5.95f 5.85f 1 0.25
Abomasum 2.95 3.70 2.80 i 0.25
S.I.-1st 1/33 6.18 5.96 5.80 1 0.25
S.I.-2nd 1/3k 6.93e 6.38f 5.809 1 0.25
S.I.-3rd 1/31 7.13c 6.18d 5.35e 1 0.25
L.I.Cecum9 5.23e 5.35e 4.75f 1 0.25

wet weight (g)
i c d e

R.R.O 4,786 5,999 5,103 1 252
Abomasum 475 891 650 1 252
S.I.-lst 1/33 498 385 395 1 252
S.I.-2nd 1/3k 359 643 476 1 252
S.I.-3rd 1/31 259g 993e 523f 1 252
L.I.Cecum9 841 966 844 1 252

TABLE 15.--Continued.

72

 

 

 

 

 

 

 

 

 

 

 

 

 

Treatments
MP MS HS SEM
Dry matter - DM (%)

R.R.Oi 11.92 11.65 11.10 1 1.08
Abomasum 8.70 9.51 9.69 1 1.08
S.I.-lst 1/3j 9.56 10.24 7.90 1 1.08
S.I.-2nd 1/3k 9.16 6.67 7.34 1 1.08
S.I.-3rd 1/31 8.55 6.94 7.40 1 1.08
L.I.Cecump 12.16 10.30 10.02 1 1.08
- — ————— Organic matter-(;)-6n DM basis ----
8.12.0i 90.25 90.53 90.34 1 0.66
Abomasum 89.81 90.67 91.73 1 0.66
S.I.-lst 1/3j 89.85 90.09 89.14 1 0.66
S.I.-2nd 1/3k 88.00 88.01 88.24 1 0.66
S.I.-3rd 1/31 84.24a 87.35b 88.98b 1 0.66
L.1.Cecum9 86.08e 85.88f 86.379 1 0.66
- _ --------- grude protein (%) on DM basis — _

R.R.Oi 11.36 10.92 11.11 1 3.68
Abomasum 18.75 20.49 20.08 1 3.68
S.I.-lst 1/3j 47.48e 38.74f 44.999 1 3.68
S.I.-2nd 1/3k 45.41 47.92 42.35 1 3.68
S.I.-3rd 1/31 31.54 33.21 28.54 1 3.68
L.1.Cecum9 18.61c 25.26d 26.63d 1 3.68

73

TABLE 15.--Continued.

 

Treatments

MP MS HS SEM

 

Other measurements

 

H-
0‘
[—1

Length of 8.1.n (cm) 1,250 1,384 1,225

Body weight (kg) 65.75 69.40 55.30 124.40

 

a’bMeans in the same row with different superscripts are different
(P<.05) O

c d e . . . .
' ' Means 1n the same row Wlth different superscripts are

different (P<.10).

e f . . . .
’ 'gMeans 1n the same row with different superscripts are

different (P<.15).
h .
Bonferroni t test.
1Rumen-reticulo-omasum.
JFirst one-third of small intestine (close to the pylorus).
kSecond one-third of small intestine.
1Third one-third of small intestine (close to the cecum).
mLarge intestine and cecum.

nSmall intestine.

74

(P<.15) in calves fed MP than soybean protein. Similar ruminal pH
values were observed by Campos and Huber (1983) for calves fed milk
but they were slightly lower on soybean protein.

The abomasum contents had a pH ranging from 2.80 to 3.70.
These values are higher than the 1.0 to 2.0 reported by Mylrea (1966a)
and Porter (1969) for calves fed whole milk 5 hr after a meal, but are
similar to data reported by Campos and Huber (1983). No significant
differences between treatments were observed.

A rapid increase of pH to about 6.0 was observed in the first
section of the small intestine. The limited capacity of the small
intestine of adult ruminants to neutralize acid digesta from the
abomasum (Smith, 1962; Phillipson and Storry, 1965; Topps et al.,
1968) in combination with large amounts of digesta passing through the
pylorus results in an acidic condition (pH of 2.0 or 3.0) in the upper
jejunun of adult ruminants. On the other hand, preruminant calves
have been shown to have a high capacity to neutralize the acid digesta
from the abomasum (Huber, 1958; Huber and Moore, 1964; Campos and Huber,
1983).

Small intestinal pH increased from the proximal for the distal
portion for calves fed MP or MS but decreased for calves fed HS. The
pH of small intestinal contents was higher (P<.10) for calves fed MP
than soybean proteins, and was higher (P<.10) for calves fed MS than
HS. Fermentation of undegraded or partially degraded carbohydrates
from soybean protein diets (mainly from HS), explains the increased
acidity of small intestine (Radostits and Bell, 1970), large intestine,

and cecal contents (Huber, 1969; Radostits and Bell, 1970).

75

Crude protein values of large intestine and cecum contents were
higher (P<.10) for calves fed soybean than milk proteins. These values
reflect the lower digestibility of soybean protein (Table 9) and agree
with data reported by Campos and Huber (1983). Length of the small
intestine and body weight were not different (Table 15).

D-xylose absorption reflects structural integrity of the small
intestine (Hill et al., 1981). In this experiment examination of
intestinal segments from each section was accomplished through use
of a scanning electron microscope equipped with a Polaroid camera.
Pictures were evaluated on a 1 to 5 scale, when 1 represented normal
morphology of villi (Figure 10) and 5 extremely abnormal (Figure 11).
Normal villi were similar to those described by Mebus et a1. (1975;
1977) for gnobiotic calf and abnormal villi were similar to those
described by Seegraber and Morrill (1982) for a calf fed soybean
protein concentrate or by Mebus et a1. (1977) for calves infected
by virus of human infantile gastro-enteritis. In this study no
differences between treatments were noted in villi morphology (Table
16); however significant differences (P<.Ol) were observed for segments
taken from different positions of the small intestine, with morphology
of distal segments more normal than the proximal. Morphology of the
first intestinal segment collected just proximal to the pylorus, was
less normal than all others for treatment MP and HS; whereas, the
first and second were different from third, fourth and sixth segments
on treatment MS. These results do not agree with those of Seegraber
and Morrill (1982) who associated impaired absorptive ability of the

intestine of calves fed the soybean portein diets with morphological

76

 

 

Figure lO.—-Normal villi from a scanning electron micrographs
of small intestinal mucosa of a calf. Most villi have a fairly
uniform appearance and surfaces show transverse furrows with Goblet
cell openings Experiment 1.

77

 

Figure ll.--An abnormal villi from scanning electron
micrographs of small intestinal mucosa of a calf Experiment 1.

78

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79

changes in intestinal structure. In this experiment calves fed soybean
protein showed lower weight gains, feed efficiencies, nutrient diges-
tibilities and xylose absorption than calves fed milk protein, but
greater differences in villi morphology were observed within animals
than between treatments.

Fecal scores were no different (P>.25) between treatments
(Table 17) and contrast with previous reports where soybean and other
non-milk proteins resulted in more diarrhea (Gorrill and Thomas, 1967;
Seegraber and Morrill, 1979; Campos, 1982). Viral infections in many
of the calves at the beginning of the experiment could have minimized
differences between treatment. There was no difference (P>.25) between
treatments in rectal temperatures, which were all within the normal
range (Table 17).

In summary, lowered digestibilities of dry matter, organic
matter, crude protein and ether extract were associated with inferior

body weight gains, poorer feed efficiencies and lower xylose absorption

TABLE l7.--Effect of feeding calves milk protein (MP), modified
soybean protein (MS) and heated soybean protein (HS)
on calves fecal scores and rectal temperatures
Experiment 1.

 

 

 

T’reatmenta'b
Variable MP MS HS SEM
Fecal scores (1-4 scale) 2.965 2.961 3.016 10.096
Rectal temperature (°C) 38.872 38.900 38.879 10.062

 

aMeans in the same row are not significantly different (P>.25).

bOrthogonal Contrast (MP vs MS + H5; MS vs HS).

80

for calves fed milk replacers containing 66% of the protein from
soybean sources (as modified soybean protein or heated soybean flour)
than 100% from milk. For these parameters, modified soybean protein
tended to be superior to heated soybean flour. No differences were
observed between any treatments for villi morphology, fecal scores or
rectal temperatures. Greater xylose clearance from the blood during

a 5 hr period was observed for calves fed soybean proteins than milk
protein, suggesting that soybean diets increased xylose metabolism and
excretion compared to milk. Gastrointestinal tract contents showed a
tendency to be more acid in the medium and distal portions of small
intestine and in the large intestine and cecum of calves fed the soybean
protein sources. More crude protein was also shown in large intestine
and cecum of calves fed the soybean protein, suggesting increased
fermentation of undergraded or partially degraded nutrients on these

diets.

Experiment 2

 

Initial body weights were similar for calves assigned to 100%
milk protein (Treatment M) or 66% of their protein as soybean protein
concentrate (Treatment S). Body weights for the last day of the 21-day
sensitization period were higher (P<.05) for calves fed M than S.
Similar treatment differences were observed for body weight gains and
average daily gains (Table 18).

However, treatment had no significant effect on body weights
during the two following lo-day periods (experimental periods) when

the calves were shifted from one treatment to the other, but calves

 

81

TABLE 18.--Effect of feeding milk protein (M) or soybean protein

concentrate (S) during the 21-day sensitization
period on calves body weights, body weight gains,
average daily gains, feed intakes, feed efficiencies
(gain/intake), rectal temperatures, fecal scores

and villi length Experiment 1.

 

 

 

 

Treatmentg
Variable M S SEM
Initial body weight (kg) 42.02 42.30 11.17
Final body weight (kg) 46.16c 41.56d 11.41
Body weight gain (kg) 4.14a -0.74b 10.55
. . a b

Average daily gain (9) 197 -35 126
Feed intake (kg) 11.21 11.12 10.33

. . a b
Gain/intake 0.37 -0.07 10.05
Rectal temperatures (°C) 38.76c 38.95d 10.06
Fecal score (1—4 scale) 2.42e 2.86f 10.18
Surgery villi length (um) 504e147.55 387f141.18 --
Final villi length (pm) 696 616 167.08
a'bMeans in the same row with different superscripts are different

(P<.001).
c'dMeans in the same row with different superscripts are different

(P<.05).
e,f

(P<.10).

9F test.

Means in the same row with different superscripts are different

82

which received no soybean protein during the sensitization period had
higher (P<.005) body weights than those sensitized with soybean protein.
Body weights were also higher (P<.05) at the end of period 2 than 1
(Table 19).

Previous sensitization to soybean protein had no significant
effect on average daily gains (ADG) during experimental periods but
treatments and periods did affect gains (Table 19). Calves fed M had
higher (P<.025) ADG than S and ADG was higher (P<.10) during period 2
than 1. Due to a significant (P<.05) sensitization x period inter-
action, a comparison between periods was made for non-sensitized and
sensitized calves (Table 20). No differences were observed between
periods for sensitized calves but a higher (P<.01) ADG was observed
for non-sensitized calves during period 2 than 1 suggesting a lowered
capacity of sensitized calves to gain weight.

Feed intake was not significantly affected by treatment during
any of the periods (Table 18 and 19). However feed intake was higher
(P<.005) for non-sensitized than previously sensitized calves during
experimental periods, and was higher (P<.025) during period 2 than 1
(Table 19). Feed intake differences were due to variation in body
weight because calves were fed according to body weight.

Feed efficiency (G/I) was higher for calves fed M than S during
both sensitization (P<.001) and experimental (P<.005) periods (Table 18
and 19). The effect of sensitization and periods on feed efficiency
was not significant during experimental periods, but sensitization x
period and sensitization x treatment interactions were (Table 19).

Due to interaction, comparisons of efficiencies between periods and

83

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84

TABLE 20.--Interaction of sensitization x period on average daily
gain (ADG) and feed efficiencies (G/I) of calvese
Experiment 2.

 

 

 

 

Non-sensitized Sensitized
Variable Period 1 Period 2 Period 1 Period 2 SEM
a b
ADG (g) 329 675 472 447 :81
c d
G/I 0.45 0.80 0.70 0.58 i 0.10

 

a . . .
'bMeans in the same row and under the same subtitle Wlth

different superscripts are different (P<.01).

C'dMeans in the same row and under the same subtitle with
different superscripts are different (P<.025).

eOrthogonal contrast.

between treatments were made for sensitized and non-sensitized calves
(Table 20 and 21). Efficiency was higher (P<.025) for non-sensitized
calves during period 2 than 1 but no significant difference between
periods was observed for sensitized calves; however efficiency was
higher (P<.05) for sensitized calves fed M than S, again suggesting
that sensitized calves were not able to gain weight with increased age
as rapidly as non-sensitized.

These growth measurements all show milk protein superior to
soybean protein concentrate (SPC). Moreover negative responses to SPC
were greater in calves previously sensitized to soybean protein (by
feeding SPC) than non-sensitized calves which were initially fed milk
protein.

The low digestibility and poor growth of calves on soybean

protein-based milk replacer has been attributed by some authors to the

85

TABLE 21.--Interaction of sensitization x treatment (M = milk
protein; S = soybean protein concentrate) on feed
efficiencies (G/I) and villi length (VL) of calvese
Experiment 2.

 

 

 

 

Non-sensitized Sensitized
M S M S SEM
a b
G/I 0.71 0.54 0.86 0.42 i 0.10
c d
VL (pm) 616 607 652 500 :51

 

a'bMeans in the same row and under the same subtitle with

different superscripts are different (P<.005).

c’dMeans in the same row and under the same subtitle with

different superscripts are different (P<.05).

eOrthogonal Contrast.

presence of soybean trypsin inhibitor (Gorrill et al., 1967; Gorrill
and Thomas, 1967); to the failure of the milk replacers to form large,
firm clots of coagulated protein in the calf abomasum resulting in a
diminished opportunity for action of pepsin (Jenkins, 1981); to the
lower hydrolitic activity of pepsin and pancreatic proteases on soybean
proteins than on milk protein (Jenkins et al., 1980). Others have
attributed the problem to a gastrointestinal allergy to soybean proteins
(Smith and Sissons, 1975; Sissons and Smith, 1976; Kilshaw and Sissons,
1979a,b) detected by appearance in serum of antibodies specific for
soybean proteins (Barratt et al., 1978; Kilshaw and Sissons, 1979a).
Villus atrophy and crypt enlogation have also resulted from feeding

soybean proteins (Kilshaw and Slade, 1982).

86

Rectal temperatures were higher (P<.05) for calves fed S than
M during the sensitization period (Table 18) and sensitized calves
tended (P<.10) to have higher rectal temperature than non-sensitized
calves during the experimental periods (Table 19). Treatment and
periods had no significant effect on temperatures during the experi-
mental periods. In spite of the rotavirus infection dectected in some
calves during the experiment and the medication used when elevated
temperature (>39.7°C) lasted for more than 12 hr, these data suggest
an allergic reaction of calves to soybean proteins.

Fecal scores tended to be higher (P<.10) for calves fed S than
M during the sensitization and experimental periods (Table 18 and 19).
Failure of milk to coagulate (Tagari and Roy, 1969; Paruelle et al.,
1972) followed by faster passage of partially digested material through
the lower gut (Colvin et al., 1969; Ternouth et al., 1975), might
explain the more liquid feces observed in calves fed SPC (Seegraber
and Morrill, 1979; Campos, 1982).

Villi length measures from bi0psy samples taken at surgery
tended to be higher (P<.10) for calves fed M than S, but no significant
differences were observed in biopsies taken on the last day of sensi-
tization period (Table 18). No treatments, sensitization or periods
effect on villi length were observed during experimental periods.
However, the sensitization x treatment interaction was significant
(Table 19). Due to this interaction, the effect of treatment on villi
length were compared for non-sensitized and sensitized animals. These

data show that treatment did not affect villi length of non-sensitized

87

calves, however sensitized calves fed M had longer villi (P<.05) than
those fed S (Table 21).

Villus atrophy associated with crypt hyperplasia and an
increased cell renewal rate has been associated with soybean protein
intolerance and coeliac disease in man (Kosnai et al., 1980; Perkkio
et al., 1981) as well as with the feeding of heated soybean flour to
calves (Kilshaw and Slade, 1982). Morphological disturbances to the
villi and lamina propria of the intestine described by Barratt et a1.
(1978) were caused by feeding toasted soybean flour to calves. A cell
mediated immune reaction was suggested by MacDonald and Ferguson (1976)
as the cause of villus atrophy, crypt hyperplasia and malaborption in
food allergy. Buckley (1982) stated that when ingested food antigens
encounter the IgE—coated mast cell, degranulation occurs, leading to
increased goblet cell activity, increased mucus secretion, edema of
mucosal epithelial cell villi, increased protein loss from the gut,
and increased absorption of foreign antigens. Kilshaw and Sissons
(l979a,b) found an increase in IgG and IgE antibodies specific to the
soybean storage globulins glycinin and beta-conglycinin in preruminant
calves fed heated soybean flour. The soybean antigens are resistent
to proteolysis; and, to a lesser degree, to the microbial action of
rumen fluid (Barratt et al., 1978).

Some calves appear to be more susceptible to soybean antigens
than others. Susceptible calves become sensitized after having been
fed heated soybean protein and the reactions become progressively worse.
Sensitivity may be retained for several weeks without reexposure to

soybean antigens (Thomas and Parrott, 1974; Kilshaw and Slade, 1980).

88

Changes in intestinal mucosa were observed 24 hr after feeding heated
soybean flour to sensitized calves, but normal morphology was again
observed after 10 days after returning to milk feeding (Kilshaw and
Slade, 1982).

In conclusion the data of this experiment suggest that calves
fed milk replacer with 66% of its protein replaced by soybean protein
concentrate (SPC) had performance inferior to calves fed all milk
protein. The higher rectal temperatures, more liquid feces and villi
atrophy suggested an allergic reaction to SPC which certainly was
related to the poor performance. Villi length data suggest that
calves were more susceptible to the villi atrophy caused by soybean
protein at 2 weeks than older ages, and effects of SPC were more

pronounced in calves which had been previously sensitized.

 

CONCLUSIONS

Replacement of 66% of the milk protein (MP) in milk replacers
with modified soybean protein (MS) or heated soybean flour (HS) resulted
in decreased calf performance as measured by body weight gains and feed
efficiencies. The poorer performance was related to a decreased
digestibility of crude protein (22% and 13% for HS and MS, respec- .\_
tively). Also, calves fed soybean protein had 16% lower xylose
absorption. The reason for the increased clearance of xylose from
the blood of calves fed MS and HS than MP is not known. From the
upper small intestine to the large intestine gastrointestinal tract
contents showed greater acidity for calves fed MS than milk protein
(MP) and pH was lower for calves fed HS than MS, confirming poorer
utilization of nutrients for HS than MS and of MS than MP. Crude protefli
content from the distal portion of small intestine was also higher for
calves fed soybean proteins. Rectal temperatures, fecal scores and
villi morphology (evaluated through scanning microscopy at 52 days of
age) were not affected by protein source. Subjective evaluation of
scans showed wide morphological variation in size and shape of villi,
with greater differences within animals than between treatments.

Replacement of 66% of the milk protein in a milk replacer with
soybean protein concentrate (SPC) resulted in lower body weight gains
and feed efficiencies in baby calves. Higher rectal temperatures,

more diarrhea and greater atrophy of villi were observed in calves

89

90

fed SPC. Also effects of SPC were more evident in calves which were
previously sensitized to soybean proteins by feeding SPC 21 days
before the experimental periods.

These data show that milk replacers containing 66% of protein
from soybean sources resulted in lower performance, decreased nutrient
digestibility, less xylose absorption and higher xylose clearance from
blood in young calves. Higher rectal temperatures, greater incidence
of diarrhea and villi atrOphy, which may suggest an allergic reaction
of calves to soybean protein, was more evident in the younger calves,
used in Experiment 2.

Further experimentation might test the ability of intestinal
mucosa of young calves to absorb undigested peptides as well as the
reasons for increased xylose clearance from the blood observed in

calves fed soybean proteins compared to milk protein.

APPENDICES

 

91

TABLE Al.--Analysis of variance for variables in Experiment 1.

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Body weight (kg)
Treatment (T) 2 421.01 1.45 NS
Block (B) 7 927.54 3.19 **
T x B (error a) 14 290.29
Period (P) 8 631.70 293.81 *****
T x P 16 10.83 5.03 *****
B x P 56 4.11 1.91 ****
Error b 112 2.15
Total body weight gain (kg)
Treatment (T) 2 141.92 3.64 *
Block (B) 7 65.56 1.68 NS
T x B (error a) 14 39.00
Period (P) 7 688.19 345.82 *****
T x P 14 8.36 4.20 ***
B x P 49 3.66 1.84 ***
Error b 98 1.99
Percent of gain on initial body weight (%)
Treatment (T) 2 775.49 3.99 **
Block (B) 7 410.91 2.12 NS
T x B (error a) 14 194.13
Age (A) 7 3,759.10 492.03 *****
T x A 14 41.40 5.42 *****
B x A 49 17.99 2.36 *****
Error b 98 7.64

 

92

TABLE Al.--Continued.

 

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Average daily gain (9)
Treatment (T) 2 238,641 11.63 ****
Block (B) 7 45,527 2.22 *
T x B (error a) 14 20,513
Age (A) 5 1,702,935 63.42 *****
T x A 10 35,983 1.34 NS
B x A 35 81,440 3.03 *****
Error b 70 26,853
Feed intake (9)
Treatment (T) 2 3.4544500x106 2.63 us
Block (B) 7 5.7209714x106 4.36 ***
T x B (error a) 14 1.3120000x106
Age (A) 5 1.4834780x107 0.74 us
T x A 10 1.5923000x105 0.01 NS
B x A 35 1.6639429x105 0.01 NS
Error b 70 2.0000360x107
Body weight gain/Feed intake
Treatment (T) 2 0.402 8.04 ****
Block (B) 7 0.149 2.98 *
T x B (error a) 14 0.050
Period (P) 5 5.380 116.95 *****
T x P 10 0.161 3.40 ****
B x P 35 0.264 5.73 *****
Error b 70 0.046
Dry matter digestibility - 2nd week (%)
Treatment 2 73.26 1.53 NS

Error 9 47.88

93

TABLE A1.--Continued.

 

 

 

 

 

 

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Organic matter digestibility - 2nd week (%)
Treatment 2 76.18 1.55 NS
Error 9 49.08
Crude protein digestibility -2nd week (%)
Treatment 2 423.53 1.55 NS
Error 9 272.65
Ether extract digestibility - 2nd week (%)
Treatment 2 201.02 0.52 NS
Error 9 385.07
Nitrogen-free extract digestibility — 2nd week (%)
Treatment 2 31.95 3.32 *
Error 9 9.62
Ash retention - 2nd week (%)
Treatment 2 88.76 1.69 NS
Error 9 52.56
Nitrogen retention - 2nd week (%)
Treatment 2 1,053.53 1.86 NS
Error 9 564.21
Dry matter digestibility - 5th week (%)
Treatment 2 48.88 5.73 **
Error 17 8.53
Organic matter digestibilityi- 5th week (%)
Treatment 2 53.48 6.86 ***
Error 17 7.79
Crude protein digestibility -5th week (%)
Treatment 2 596.87 21.75 *****

Error 17 27.44

 

94

TABLE Al.--Continued.

 

 

 

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Ether extract digestibility -5th week (%)
Treatment 2 13.48 3.39 **
Error 17 3.97
Nitrogen-free extract digestibility - 5th week (%)
Treatment 2 8.61 0.94 NS
Error 17 9.08
Ash retention - 5th week (%)
Treatment 2 9.48 0.36 NS
Error 17 26.11
Nitrogen retention - 5th week (%)
Treatment 2 856.84 16.80 *****
Error 17 50.99
Plasma urea nitrogen (mg/100 ml)
Treatment (T) 2 4.12 0.36 NS
Block (B) 7 7.71 0.67 NS
T x B (error a) 14 11.47
Age (A) l 0.17 0.02 NS
T x A 2 20.28 1.82 NS
B x A 7 10.32 0.93 NS
Error b 14 11.12
Plasma xylose concentration - oral dose (mg XYL/100 m1)
Treatment (T) 2 528.17 5.22 **
Block (B) 7 136.72 1.35 NS
T x B (error a) 14 101.18
Time (M) 7 1,192.82 24.45 *****
T x M 14 29.01 0.59 NS
B x M 49 55.71 1.14 NS

Error b 98 48.78

95

TABLE A1.--Continued.

 

 

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Plasma xylose concentration - IV dose (log mg XYL/100 ml)
Treatment (T) 2 0.0568 2.90 *
Block (B) 7 0.0239 1.22 NS
T x B (error a) 14 0.0196
Time (M) 7 0.7043 140.86 *****
T x M 14 0.0088 1.76 *
B x M 49 0.0056 1.12 NS
Error b 98 0.0050
Urine xylose concentration - oral dose (mg XYL/100 m1)
Treatment 2 20.93 0.76 NS
Error 19 27.69
Urine xylose concentration - IV dose (mg XYL/lOO m1)
Treatment 2 94.03 1.28 NS
Error 17 73.34
Gastrointestinal tract content - pH
Treatment (T) 2 1.7504 8.95 *
Animal/T (error a) 3 0.1956
Sample (B) 5 8.9920 72.28 *****
T x B 10 0.2735 2.20 *
Error b 15 0.1244
Gastrointestinal tract content - wet matter (9)
Treatment (T) 2 616,709 4.23 NS
Animal/T (error a) 3 145,901
Sample (8) 5 22,066,631 173.21 *****
T x B 10 116,919 0.92 NS
Error b 15 127,399

96

TABLE Al.--Continued.

 

 

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Gastrointestinal tract content - dry matter (%)
Treatment (T) 2 3.86 0.50 NS
Animal/T (error a) 3 7.68
Sample (B) 5 15.21 6.57 ****
T x B 10 1.46 0.63 NS
Error b 15 2.31
Gastrointestinal tract content - organic matter (%)
Treatment (T) 2 6 . 04 2 . 05 NS
Animal/T (error a) 3 2.95
Sample (B) 5 18.42 21.15 *****
T sz 10 2.30 2.65 **
Error b 15 0.87
Gastrointestinal tract content - crudegprotein (%)
Treatment (T) 2 1.09 0.05 NS
Animal/T (error a) 3 22.93
Sample (B) 5 1,103.34 40.83 *****
T x B 10 20.94 0.78 NS
Error b 15 27.02
Small intestine length (cm)
Treatment 2 14,584 1.98 NS
Error 3 7,341
Slaughtered calves body weight (kg)
Treatment 2 214 0.18 NS

Error 5 1,190

TABLE Al.--Continued.

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Villi evaluation (1-5 scale)
Treatment (T) 2 1.6722 0.40 NS
Evaluators (B) 4 5.1472 1.22 NS
T x B 8 0.2347 0.06 NS
Animal/T (A/T) 3 4.2277
B x A/T 12 0.5333 0.86 NS
Sample (S) 5 18.9922 30.69 *****
T x S 10 3.1322 5.06 *****
Error b 135 0.6188
Fecal scores (1-4 scale)
Treatment (T) 2 0.0601 0.10 NS
Block (B) 7 0.2779 0.46 NS
T x 8 (error a) 14 0.5953
Age (A) 7 5.6209 28.24 *****
T x A 14 0.2267 1.13 NS
B x A 49 0.3114 1.56 **
Errob b 98 0.1990
Retal temperature (°C)
Treatment (T) 2 0.0100 0.05 NS
Block (B) 7 0.2529 1.38 NS
T x B 14 0.1836
Age (A) 5 0.6520 10.79 *****
T x A 10 0.0310 0.51 NS
B x A 35 0.1086 1.79 **
Error b 70 0.0604

 

98

TABLE A1.--Continued.

aNS = nonsignificant (P>.10).

* = P<.10.

** = P<.05.
*** = P<.01.
**** = P<.005.
***** = P<.001.

99

TABLE A2.-~Ana1ysis of variance for variables in Experiment 2 (21-day

 

 

 

 

 

 

 

 

 

 

period).
Source of F Significance
variation d.f. Mean square ratio levela
Initial body weight (kg)
Treatment 1 0.3 0.03 NS
Error 14 10.9
Final body weight (kg)
Treatment 1 84.5 5.31 **
Error 14 15.9
Body weight gain (kg)
Treatment 1 95.2 41.39 ***
Error 14 2.3
Average daily gain (g)
Treatment 1 215,992 39.88 ***
Error 14 5,415
Feed intake (kg)
Treatment 1 0.0331 0.04 NS
Error 14 0.8726
Body weight gain/Feed intake
Treatment 1 0.7700 39.07 ***
Error 14 0.0197
Rectal temperature (°C)
Treatment 1 0.1406 5.02 **
Error 14 0.0280
Fecal score (1-4 scale)
Treatment 1 0.7832 3.14 *
Error 14 0.2498

100

 

 

 

 

 

TABLE A2.-~Continued.
Source of F Significance
variation d.f. Mean square ratio levela
Surgery villi length (um)
Treatment 1 46,600 3.43 *
Error 12 13,567
Final villi length (um)
Treatment 1 25,360 0.70 NS
Error 14 35,995
aNS = nonsignificant (P>.10).

* = P<.10.

** = P<.05.
*** = P<.001.

101

TABLE A3.--Ana1ysis of variance for variables in Experiment 2 (lO-day

 

 

 

 

 

period).

Source of F Significance

variation d.f. Mean square ratio levela
Body weight (kg)
Sensitization (S) 1 148.1 12.55 ****
Animal/S (error a) 14 11.8
Treatment (T) 1 13.4 0.35 NS
Period 1 251.5 6.56 **
S x T 1 2.5 0.07 NS
Residual error 13 38.3
Average daily gain (9)
Sensitization (S) 1 14,323 1.16 NS
Animal/S (error a) 14 12,347
Treatment (T) 1 395,828 7.61 ***
Period (P) 1 205,922 3.96 *
S x T 1 68,172 1.31 NS
8 x P 1 275,096 5.29 **
Residual error 12 52,019
Feed intake (kg)
Sensitization (S) 1 4.18 16.07 ****
Animal/S (error a) 14 0.26
Treatment (T) 1 0.08 0.10 NS
Period (P) 1 8.54 9.81 ***
S x T l 0.04 0.05 NS
S x P 1 0.05 0.06 NS
Residual error 12 0.87

102

TABLE A3.--Continued.

 

 

 

 

 

Source of F Significance
variation d.f. Mean square ratio levela
Body weight gain/Feed intake
Sensitization (S) 1 0.0031 0.14 NS
Animal/S (error a) 14 0.0219
Treatment (T) 1 0.7275 8.68 ***
Period (P) 1 0.1082 1.29 NS
S x T 1 0.1508 1.80 NS
S x P 1 0.4596 5.48 **
Residual error 12 0.0838
Rectal temperatures (°C)
Sensitization (S) 1 0.120 4.32 *
Animal/S (error a) 14 0.027
Treatment (T) 1 0.060 1.01 NS
Period (P) 1 0.088 1.49 NS
S x T 1 0.046 0.78 NS
Residual error 13 0.059
Fecal score (1-4 scale)
Sensitization (S) 1 0.2112 0.92 NS
Animal/S (error a) 14 0.2306
Treatment (T) 1 1.9012 3.27 *
Period (P) 1 1.3612 2.34 NS
S x T 1 0.6050 1.04 NS
Residual error 13 0.5821

103

TABLE A3.--Continued.

 

 

 

Source of F Significance
variation d.f. Mean square ratio level
Villi leggth (um)
Sensitization (S) 1 9,940 1.04 NS
Animal/S (error a) 14 9,566
Treatment (T) 1 51.681 2.44 *
Period (P) 1 10,011 0.47 NS
S x T 1 40,186 1.90 *
Residual error 13 21.203

 

aNS = nonsignificant (P>.10).

* = P<.10.

** = P<.05.
*** = P<.025.
**** = P<.005.

B IBL IOGRAPHY

 

BIBLIOGRAPHY

Akinyele, I.O., and K.E. Harshbarger. 1983. Performance of young
calves fed soybean protein replacers. J. Dairy Sci. 66:825.

Almiquist, H.J., E. Mecchi, H.F. Kratzer, and C.R. Grau. 1942.
Soybean protein as a source of amino acids for the chick.
J. Nutr. 24:385.

Alpan, S.O., J.E. Oldfield, D.W. Claypool, and G.O. Kohler. 1979.
Digestibility of alfalfa protein concentrate (Pro-Xan) in
milk replacer diets for calves. J. Dairy Sci. 62:86
(Suppl. 1).

Appleman, R.D., and D.E. Otterby. 1973. Using colostrum to raise
dairy calves. Agr. Ext. Serv. Univ. Minn. Dairy Husbandry
No. 9.

Ash, R.W. 1964. Abomasal secretion and emptying in suckled calves.
J. Physiol. 172:425.

Association of Official Agricultural Chemists. 1980. Official Methods
of Analysis. 13th edition, A.O.A.C., washington, D.C.

Bang-Jensen, V., B. Foltman, and W. Rombauts. 1964. Studies on
rennin. X: On the proteolytic specificity of rennin.
C.R. Trav. Lab. Carlsberg 34:326.

Barr, G.W., S.R. Martin, M.L. Kakade, P.J. Ryan, and F.M. Crane.
1978. Influence of modified soy protein in milk replacers
on calf performance and health. J. Dairy Sci. 61:169
(Suppl. 1).

Barratt, M.E.J., P.J. Strachan, and P. Porter. 1978. Antibody
mechanisms implicated in digestive disturbances following
ingestion of soya protein in calves and piglets. Clin. Exp.
Immunol. 31:305.

Benson, J.A. Jr., P.J. Culver, S. Ragland, C.M. Jones, G.D. Drummey,
and E. Bougas. 1957. The D-xylose absorption test in
malabsorption syndromes. The New England J. of Medicine
256:335.

104

105

Berry, T.H., D.E. Becker, O.G. Rasmussen, A.H. Jensen, and H.W. Norton.
1962. The limiting amino acids in soybean protein. J. Anim.
Sci. 21:558.

Beynen, A.C., and L.G.M. van Gils. 1983. Post prandial changes in the
levels of lipids glucose urea and nonprotein nitrogen in the
serum of veal calves fed milk replacers containing either
skim milk powder or soybean protein concentrate. Z. Tierphysiol.
Thierernaehr Futtermittelkd. 40:49.

Bloch, H.J., D.B. Bloch, M. Stearns, and W.A. Walker. 1979. Intestinal
uptake of macromolecules. VI. Uptake of protein antigen
in vivo in normal rats and in rats infected with Nippostrongylus

 

brasiliensis or subjected to milk systemic anaphylaxis.
Gastroenterology 77:1039.

 

Bolton, J.R., A.M. Merritt, R.E. Cimprich, C.F. Ramberg, and W.
Streett. 1976. Normal and abnormal xylose absorption in the
horse. Cornell Vet. 66:183.

Brien, F.S., D.A. Turner, E.M. Watson, and J.H. Gueddes. 1952. Study
of carbohydrate and fat absorption from normal and diseased
intestine in man: absorption and excretion of d-xylose.
Gastroenterology 20:287.

Bring, A.N., and G.W. Barr. 1979. Effect of protein source of milk
replacer on performance of dairy calves in cold housing.
J. Dairy Sci. 62:100 (Suppl. 1).

Brumbaugh, J.H., and C.B. Knodt. 1952. Milk replacements for dairy
calves. J. Dairy Sci. 35:336.

Buckley, R.H., and D. Metcalfe. 1982. Food allergy. J. of the
American Medical Assoc. 248:2627.

Butterworth, C.E., Jr., E. Perez-Santiago, J.M. Jesus, and R. Santini.
1959. Studies on the oral and parenteral administration of
D(+) xylose. The New England J. of Medicine 261:157.

Campos, O.F. -l982. Spray dried fish solubles, soy protein concentrate
and limestone in milk replacers for young calves. Ph.D.
Thesis, Michigan State University, East Lansing.

Campos, 0.F., and J.T. Huber. ~1983. Performance and digestion by
calves from limestone added to milk replacers containing soy
protein concentrate. J. Dairy Sci. 66:2365.

Campos, O.F., J.T. Huber, and W.G. Bergen. l982a. Partial substitutflx1
of milk protein with spray-dried fish solubles or soy protein
concentrates in milk replacers. J. Dairy Sci. 65:1240.

106

Campos, O.F., J.T. Huber, J.L. Morrill, R.K. Brownson, A.D. Dayton,
H.J.S. Harrison, and R.G. warner. 1982b. Spray-dried fish
solubles or soy protein concentrate in milk replacer
formulations. J. Dairy Sci. 65:97.

Carroll, R.W., G.W. Hensley, and W.R. Graham, Jr. 1952. The site
of nitrogen absorption in rats fed raw and heat-treated
soybean meals. Science 115:36.

Christison, G.I., and J.M. Bell. 1977. The disappearance of vegetable
protein from abomasum of young calves. Can. J. Anim. Sci.
57:882 (abstr).

Church, D.C. 1984. Livestock Feeds and Feeding. Chapter 8, p. 135.
O & B Brooks, Inc., Corvallis, Oregon.

Clary, J.J., G.E. Mitchell, Jr., C.O. Little, and N.W. Bradley. 1969.
Pancreatic amylase activity from ruminants fed different
rations. Can. J. Physiol. Pharmacol. 47:161.

Coates, M.E., D. Hewitt, and P. Golob. 1970. A comparison of the
effects of raw and heated soya—bean meal in diets for
germ—free and conventional chicks. Brit. J. Nutr. 24:213.

Colvin, B.M., R.A. Lowe, and H.A. Ramsey. 1969. Passage of digesta
from the abomasum of a calf fed soy flour milk replacers and
whole milk. J. Dairy Sci. 52:687.

Colvin, B.M., and H.A. Ramsey. .1968. Soy flour in milk replacers
for young calves. J. Dairy Sci. 51:898.

Colvin, B.M., and H.A. Ramsey. 1969. Growth of young calves and rats
fed soy flour treated with acid or alkali. J. Dairy Sci.
52:270.

Coombe, N.B., and R.C. Siddons. 11973. Carbohydrases of the bovine
small intestine. Br. J. Nutr. 30:269.

Coombe, N.B., and R.H. Smith. 1972. Carbohydrate hydrolysis in the
bovine small intestine. Rep. Natn. Instit. Res. Dairy 1971-2:
67.

Davicco, M.J., L. Lefaivre, P. Thivend, and J.P. Barlet. 1979.
Feedback regulation of pancreatic secretion in the young
milk-fed calf. Ann. Biol. anim. Bioch. Biophys. 19:1147.

Debas, H.T., S.J. Konturek, J.H. walsh, and M.I. Grossman. 1974.
Proof of a pyloric-oxyntic reflex for stimulation of acid
secretion. Gastroenterology 66:526.

 

107

DeGregorio, R.M., G.W. Barr, N. Stahel, and F.M. Crane. 1982.
Modified soy protein as a protein source in calf milk
replacer. J. Dairy Sci. 65(Suppl. 1):123.

DeGroot, A.P., and P. Slump. 1969. Effects of severe alkali treatment
or proteins on amino acid composition and nutritive value.
J. Nutr. 98:45.

Dollar, A.M., and J.W.B. Porter. 1957. Utilization of carbohydrates
by the young calf. Nature 179:1299.

Dollar, A.M., and J.W.G. Porter. 1959. Some aspects of carbohydrate
utilization by young calves. Proc. XVth Int. Dairy Congr.
1:185.

Eggum, B.O. 1970. Blood urea measurement as a technique for assessing
protein quality. Br. J. Nutrition 24:983.

Emmons, D.B., and E.E. Lister. 1976. Quality of protein in milk
replacers for young calves. I. Factores affecting in vitro
curd formation by rennet (chymosin, rennin) from reconstituted
skimmilk powder. Can. J. Anim. Sci. 56:317.

Emmons, D.B., E.E. Lister, and J.D. Jones. 1976. Quality of protein
in milk replacers for young calves. IV. Rennet (chymosin,
rennin) coagulation of reconstituted skimmilk powder containing
added proteins, fat, calcium, phosphate and citrate. Can. J.
Anim. Sci. 56:339.

Fawcet, J.H., and J.E. Scott. 1960. A rapid and precise method for
the determination of urea. J. Clin. Path. 13:156.

Flipse, R.J., C.F. Hoffman, H.D. Webster, and G.W. Duncan. 1950.
Carbohydrate utilization in the young calf. II. The nutritive
value of starch and the effect of lactose on the nutritive
values of starch and corn syrup in synthetic milk. J. Dairy
Sci. 33:557.

Foldager, J. 1976. The requirement of methionine and total sulfur
amino acids in the pre-ruminant calf. M.S. Thesis, Michigan
State University, East Lansing.

Frantzen, J.P., R. Toullec, and C.M. Mathieu. 1971. Influence de la
coagulation des proteines sur l'utilization digestive d'un
lait de replacement par 1e veau preruminant. 10th Congr. Int.
Zootech., p. l, Versailles.

Gardner, R.W., D.L. Martin, and D.J. weber. 1982. Allergenicity of
soybean milk replacers fed to calves. J. Dairy Sci. 65(Suppl.1):
122.

108

Garlich, J.D., and M.C. Nescheim. 1966. Relationship of fraction of
soybeans and a crystalline soybean trypsin inhibitor to the
effects of feeding unheated soybean meal to chicks. J. Nutr.
88:100.

Garnot, P., R. Toullec, J.L. Thapon, P. Martin, M.T. Hoang, C.M.
Mathieu, and B.R. Dumas. 1977. Influence of age, dietary
protein and weaning on calf abomasal enzymic secretion.

J. Dairy Res. 44:9.

Genskow, R.D., R.E. Harshbarger, and R.M. Wendlandt. 1968. Observa-
tions on vitamin deficiencies in calves fed a milk replacer
containing lowbash fish meal. J. Dairy Sci. 51:973 (abstr).

Gertler, A., and Z. Nitsan. 1970. The effect of trypsin inhibitors
upon the pancreato peptidase E, trypsin, chymotrypsin and
amylase in the pancreas and intestinal tract of chicks, as
compared to raw and heated soybean diets. Br. J. of
Nutrition 24:893.

Gill, J.L. 1978a. Design and Analysis of Experiments in the Animal
and Medical Sciences. Vol. 1. The Iowa State university
Press, Ames, Iowa.

Gill, J.L. 1978b. Design and Analysis of Experiments in the Animal
and Medical Sciences. Vol. 2. The Iowa State University
Press, Ames, Iowa.

Gill, J.L. 1978c. Design and Analysis of Experiments in the Animal
and Medical Sciences. vol. 3 - Appendices. The Iowa State
University Press, Ames, Iowa.

Gillespi, J.H. 1971. An evaluation of partially deboned fish protein
concentrate.as an ingredient in calf milk replacers. M.S.
Thesis, University of Illinois, Urbana.

Gorrill, A.D.L. 1970. Physical and chemical characteristics of
soybean and milk proteins before and after treatment with
dilute alkali. Can. J. Anim. Sci. 50:745.

Gorrill, A.D.L., J.D. Jones, and J.W.G. Nicholson. 1976. Low and high
glucosinolate rapeseed flours and rapeseed oil in milk
replacers for calves: their effects on growth, nutrient
digestion and nitrogen retention. Can. J. Anim. Sci. 56:409.

Gorrill, A.D.L., and J.W.G. Nicholson. 1969. Growth, digestibility
and nitrogen retention by calves fed milk replacers containing
milk and soybean proteins, supplemented with methionine.

Can. J. Anim. Sci. 49:315.

109

Gorrill, A.D.L., and J.W.G. Nicholson. 1971. Effect of soybean trypsin
inhibitor, diarrhea, and diet on flow rate, pH, proteolytic
enzimes and nitrogen fractions in calf intestinal digesta.

Can. J. Anim. SCi. 51:377.

Gorrill, A.D.L., and J.W.G. Nicholson. 1972a. Use of the Williams
Polytron to homogenize fat and disperse insoluble ingredients
in high-fat liquid milk replacers. Can. J. Anim. Sci. 52:477.

Gorrill, A.D.L., and J.W.G. Nicholson. 1972b. Alkali treatment of
soybean protein concentrate in milk replacers: its effect on
digestion, nitrogen retention and growth of lambs. Can. J.
Anim. Sci. 52:665.

Gorrill, A.D.L., J.W.G. Nicholson, E. Larmond, and H.E. Power. 1975.
Comparison of fish protein sources and milk byproducts in
milk replacers for calves. Can. J. Anim. Sci. 55:269.

Gorrill, A.D.L., J.W.G. Nicholson, and H.E. Power. 1972. Effects of
milk, fish and soybean proteins in milk replacers, and feeding
frequency on performance of dairy calves. Can. J. Anim. Sci.
52:321.

Gorrill, A.D.L., and J.W. Thomas. 1965. Proteolytic activity of the
bovine pancreas. J. Anim. Sci. 24:882 (abstr).

Gorrill, A.D.L., and J.W. Thomas. 1967. Body weight changes, pancreas
size and enzyme activity, and proteolytic enzyme activity and
protein digestion in intestinal contents from calves fed soybean
and milk protein diets. J. Nutr. 92:215.

Gorrill, A.D.L., J.W. Thomas, W.E. Stewart, and J.L. Morrill. 1967.
Exocrine pancreatic secretion by calves fed soybean and milk
protein diets. J. Nutr. 92:86.

Gorrill, A.D.L., D.M. Walker, J.D. Jones, and J.W.G. Nicholson. 1974.
Rapeseed protein and amino acid supplements in milk replacers
for lambs: their effects on nutrient digestion and nitrogen
retention. Can. J. Anim. Sci. 54:611.

Gregory, R.A. 1974. The gastrointestinal hormones. A review of recent
advances. J. Physiol. 241:1.

Guilloteau, P., T. Corring, P. Garnot, P. Martin, R. Tbullec, and
G. Durand. 1983. Effects of age and weaning on enzymes
activities of abomasum.and pancreas of the lamb. J. Dairy
Sci. 66:2373.

Guilhoteau, P., R. Toullec, J. Culioli, D. Douaron. 1977. Utilization
of proteins by the preruminant veal calf. 5. Apparent
digestibility of fish, soybean and field bean proteins.

Ann. Zootech. 26:15.

110

Guilloteau, P., R. Toullec, and P. Partureau-Mirand. 1979. Influence
de la vitesse d'evacuation gastric des proteines et des
lipides sur utilization digestive chez le veau preruminant.
Ann. Biol. anim. Biochim. Biophys. 19:955.

Guilhermet, R., C.M. Mathieu, and R. Toullec. 1973. Observations
sur 1e transit des aliments liquides an niveau de la gouttiere
es0phafiense chez le veau preruminant et ruminant. Ann. Biol.
anim. Biochim. Biophys. 13:715.

Haines, P.C., and R.L. Lyman. 1961. Relationship of pancreatic
enzymes secretion to growth inhibition in rats fed soybean
trypsin inhibitor. J. Nutr. 74:445.

Harshbarger, K.E., and T.J. Gelwicks. 1965. Fish flour as a protein
source in milk replacers for dairy calves. J. Dairy Sci.
48:788 (abstr).

Harper, A.A. 1972. Progress report. The control of pancreatic
secretion. Gut. 13:308.

Hays, V.W., V.C. Speer, P.A. Hartman, and D.V. Catron. 1959. The
effect of age and supplemental of amino acids on the utiliza-
tion of milk and soya proteins by the young pig. J. Nutr.
69:179.

Heilskov, N.S.C. 1951a. Animal lactase. I. Determination of lactase
activity. Acta. Physiol. Scand. 22:267.

Heilskov, N.S.C. 1951b. Studies on animal lactase. II. Distribution
in some of the glands of the digestive tract. Acta. Physiol.
Scand. 24:84-89.

Henschel, M.J., W.B. Hill, and J.W.G. Porter. 1961a. The development
of proteolytic enzymes in the abomasum of the young calf.
Proc. Nutr. Soc. 20 x1.

Henschel, M.J., W.E. Hill, and J.W.G. Porter. 1961b. Proteolysis of
milk and synthetic milks in the abomasum of the young calf.
Proc. Nutr. Soc. 20 xli.

Henschel, M.J., W.E. Hill, and J.W.G. Porter. 1963. Carbohydrated
digestion in the small intestine of the young steer. Proc.
Nutr. Soc. 22 v.

Henrikesen, F.W., and H. Worning. 1969. The mutual influence of
gastrin and secretin on the external pancreatic secretion
in dogs. Acta Physiol. Scand. 76:67.

Hiatt, H.H. 1957. Glycogen formation via pentose phosphate pathway
in mice in vivo. J. Biol. Chem. 224:851.

111

Hill, F.W.G., D.E. Kidder, and J. Frew. 1970. An xylose absorption
test for the dog. Vet. Rec. 87:250.

Hill, J.K. 1968. Abomasal function. In: Handbook of Physiology.
C.F. Code, editor. Amer. Physiol. Soc., Washington, D.C.

Hill, J.K. 1968. Alimentary Canal. In: Handbook of Physiology.
C.F. Code, editor. Amer. Physiol. Soc., Washington, D.C.

Hill, R., E. Cutz, G. Cherian, D.G. Gall, and J.R. Hamilton. 1981.
An evaluation of D-xylose absorption measurements in children
suspected of having small intestinal disease. The J. of
Pediatrics 99:245.

Hochster, R.M., and R.W. Watson. 1953. Xylose isonerase. J. Am.
Chem. Soc. 75:3284.

Hooks, R.D., V.W. Hays, V.C. Peer, and J.T. MaCall. 1965. Effect of
raw soybeans on pancreatic enzyme concentrations and performance
of pigs. J. Anim. Sci. 24:894 (abstr).

Houpt, T.R. 1977. Water, electrolytes, and acid-base balance.
In: Duke's Physiology of Domestic Animals. M.J. Swenson,
editor. Cornell University Press, Ithaca, New York.

Huber, J.T. 1958. Relationship of age and diet to digestive enzyme
activity in calf. M.S. Thesis, Iowa State University, Ames,
Iowa.

Huber, J.T. 1969. Calf nutrition and development of the digestive
and metabolic apparatus of the calf. J. Dairy Sci. 52:1303.

Huber, J.T., and O.F. Campos. 1982. Enzymatic hydrolysate of fish,
spray-dried fish solubles, and soybean protein concentrate
in milk replacers for calves. J. Dairy Sci. 65:2351.

Huber, J.T., N.L. Jacobson, R.S. Allen, and P.A. Hartman. 1961a.
Digestive enzyme activities in the young calf. J. Dairy
Sci. 44:1494.

Huber, J.T., N.L. Jacobson, A.D. McGilliard, and R.S. Allen. 1961b.
Utilization of carbohydrates introduced directly into the
omaso-abomasal area of the stomach of cattle of various ages.
J. Dairy Sci. 44:321.

Huber, J.T., N.L. Jacobson, A.D. McGilliard, J.L. Morrill, and R.S.
Allen. 1961c. Digestibility and diurnal excretion patterns
of several carbohydrates fed to calves by nipple pail.

J. Dairy Sci. 44:1484.

112

Huber, J.T., and W.E.C. Moore. 1964. Short-chain fatty acid concen-
trations posterior to the stomach of calves fed normal and
milk diets. J. Dairy Sci. 47:1421.

Huber, J.T., S. Natrajan, and C.B. Polan. 1967. Adaptation to starch
in steers fed by nipple pail. J. Dairy Sci. 50:1161.

Huber, J.T., S. Natrajan, and C.E. Polan. 1968. Varying levels of
starch in calf milk replacers. J. Dairy Sci. 51:1081.

Huber, J.T., R.J. Rifkin, and J.M. Keith. 1964. Effect of level of
lactose upon lactase concentrations in the small intestines
of young calves. J. Dairy Sci. 47:789.

Huber, J.T., and L.M. Slade. 1967. Fish flour as a protein source
in calf milk replacers. J. Dairy Sci. 50:1296.

Jenkins, R.J. 1981. Pepsin and pancreatin supplementation of calf
milk replacer containing soy protein. Can. J. Anim. Sci.
61:469.

Jenkins, R.J. 1982. Effect of acid-precipitated casein in calf milk
replacer on rennet clot. J. Dairy Sci. 65:1652.

Jenkins, R.J., and D.B. Emmons. 1982. Evidence for beneficial effect
of chymosin-casein clots in abomasum on calf performance.
Nutrition Reports International 26:635.

Jenkins, K.J., D.B. Emmons, E. Larmond, and F.D. Sauer. 1982.
Soluble, partially hydrolyzed fish protein concentrate in
calf milk replacers. J. Dairy Sci. 65:784.

Jenkins, K.J., S. Mahadevan, and D.B. Emmons. 1980. Susceptibility
of protein used in calf milk replacers to hydrolysis by
various proteolytic enzymes. Can. J. Anim. Sci. 60:907.

Jones, G.M. 1975. Dairy replacement heifers. V.P.I. & S.U. Dairy
Guideline Series 291.

Kakade, M.L., R.M. Thompson, W.E. Engelstad, G.C. Behrens, and R.D.
Yoder. 1974. Nutritional significance of soybean trypsin
inhibitor in calves. J. Dairy Sci. 57:650 (abstr).

Kakade, M.L., R.M. Thompson, W.E. Engelstad, G.C. Behrens, R.D. Yoder,
and F.M. Crane. 1976. Failure of soybean trypsin inhibitor
to exert deleterious effect in calves. J. Dairy Sci. 59:1484.

Kay, R.N.B. 1966. The influence of salive on digestion in ruminants.
World Rev. Nutr. Diet. 6:292.

Kellor, R.L. 1974. Defatted soy flour and grits. J. Amer. Oil Chem.
Soc. 51:77A.

113

Kilshaw, P.J., and J.W. Sissons. 1979a. Gastrointestinal allergy to
soybean protein in preruminant calves. Antibody production
and digestive disturbances in calves fed heated soybean flour.
Res. Vet. Sci. 27:361.

Kilshaw, P.J., and J.W. Sissons. 1979b. Gastrointestinal allergy to
soybean protein in preruminant calves. Allergenic constituents
of soybean products. Res. Vet. Sci. 27:366.

Kilshaw, P.J., and H. Slade. 1980. Passage of ingested protein into
the blood during gastrointestinal hypersensitivity reactions:
experiments in the preruminant calf. Clin. Exp. Immunol.
41:575.

Kilshaw, P.J., and H. Slade. 1982. Villus atrophy and crypt enlogation
in the small intestine of preruminant calves fed with heated
soybean flour or wheat gluten. Res. Vet. Sci. 33:305.

Kirton, A.H., D.J. Paterson, and N.H. Clarke. 1971. Slaughter informa-
tion and rennin production from bobby calves. N.Z.J. Agric.
Res. 14:397.

Kosnai, I., P. Kuitunen, E. Savilahti, J. Rapola, and J. Kohegyi. 1980.
Cell kinetics in the jejunal crypt epithelium in malaborption
syndrome with cow's milk protein intolerance and in coeliac
disease of childhood. Gut. 21:1041.

Larsen, H.J., G.E. Stoddard, N.L. Jacobson, and R.S. Allen. 1956.
Digestion and absorption of various carbohydrates posterior
to the rumino-reticular area of the young bovine. J. Anim.
Sci. 15:473.

Larson, L.L., F.G. Owen, J.L. Albright, R.D. Appleman, R.C. Lamb, and
L.D. Muller. 1977. Guidelines toward more uniformity in
measuring and reporting calf experimental data. J. Dairy Sci.
60:989.

Lassen, S. 1965. Fish solubles. In: Fish as Food. George Borgstrom,
editor. Vol. III, page 281. Academic Press, New York and
London.

Liang, Y.T., J.L. Morrill, and J.L. Noordsky. .1967. Absorption and
utilization of volatile fatty acids by the young calf.
J. Dairy Sci. 50:1153.

Lister, E.E., and D.B. Emmons. 1976. Quality of protein in milk
replacers for young calves. II. Effects of heat treatment
of skim milk powder and fat levels on calf growth, feed
intake and nitrogen balance. Can. J. Anim. Sci. 56:327.

114

MacDonald, T.T., and A. Ferguson. 1976. Hypersensitivity reactions
in the small intestine. 2. Effects of allograft rejection on
mucosal architecture and lymphoid cell infiltrate. Gut.
17:81.

Makdani, D.D., W.G. Bergen, O. Mickelsen, and J.T. Huber. 1971a.
Factors influencing the nutritive values of
1,2-dichloroethane-extracted fish protein concentrate
in rat diets. Amer. J. Clin. 24:1384.

Makdani, D.D., J.T. Huber, and R.L. Michel. 1971b. Nutritional
value of 1,2-dichloroethane extracted fish protein concentrate
for young calves fed milk replacer diets. J. Dairy Sci.
54:886.

Mathieu, C.M., and P. Thivend. 1968. Digestion et utilisation des
aliments par 1e veau preruminant a l'engrais. III.
Replacement des matieres grasses du lait par differents
amidons. Ann. Biol. anim. Biochim. Biophys. 8:249.

Mathieu, C.M., P. Thivend, and P.E. Barre. 1970. Digestion et
utilisation des aliments par le veau preruminant a l'engrais.
V. Remplacement des matieres grasses du lait par des dextrines.
Ann. Biol. anim. Biochim. Biophys. 10:253.

Matre, T. 1970. Proteinkvaliteten i erstatningsdmojolk til kalvar.
Nord. Jordbruksforsk. 53:3368.

Maynard, L.A., and L.C. Norris. 1923. A system of rearing dairy
calves with limited use of milk. J. Dairy Sci. 6:483.

McCormick, R.J., and W.E. Stewart. 1967. Pancreatic secretion in
bovine calf. J. Dairy Sci. 50:568.

Mebus, C.A., L.E. Newman, and E.L. Stair. 1975. Scanning electron,
light, and transmission electron microscopy of intestine of
gnotobiotic calf. Am. J. Vet. Res. 36:985.

Mebus, C.A., R.G. wyatt, and A.Z. Kapikiau. 1977. Intestinal lesions
induced in gnotobiotic calves by the virus of human infantile
gastroenteritis. Vet. Pathol. 14:273.

Michel, R.L., D.D. Makdani, J.T. Huber, and A.E. Sculthorpe. 1972.
Nutritional myopathy due to vitamin E deficiency in calves
fed fish protein concentrate as the sole source of protein.
J. Dairy Sci. 55:498.

Mickelsen, O., and M.G. Yang. 1966. Naturally occurring toxicants
in foods. Fed. Proc. 25:104.

Miller, D.S. 1956. The nutritive values of fish proteins. J. Sci.
Food Agr. 7:337.

115

Morrill, J.L., N.L. Jacobson, A.D. McGilliard, and D.K. Hotchkiss.
1965. Use of a re-entrant ileal fistula to study carbohydrate
utilization by the young bovine. J. Nutr. 85:429.

Morrill, J.L., S.L. Melton, A.D. Dayton, E.J. Guy, and M.J. Pallansch.
1971. Evaluation of milk replacers containing a soy protein
concentrate and high whey. J. Dairy Sci. 54:1060.

Morrison, A.E., and J.M. McLaughlan. 1961. Variability in nutritional
value of fish flour. Can. J. Biochem. Physiol. 39:511.

Morrison, A.E., Z.I. Sabry, and E.J. Middleton. 1962. Factors
influencing the nutritional values of fish flour. I. Effects
of extraction with chloroform or ethylene dichloride.

J. Nutr. 77:97.

Munro, I.C., and A.B. Morrison. 1967. Factors influencing the
nutritional value of fish flour. V. Chlorocholine chloride,
a toxic material in samples extracted with 1,2-dichloroethane.
Can. J. Biochem. Physiol. 45:1049.

Mylrea, P.J. 1966a. Digestion of milk in young calves. I. Flow and
acidity of the contents of the small intestine. Res. Vet.
7:333.

Mylrea, P.J. 1966b. Digestion of milk in young calves. II. The
absorption of nutrients from the small intestine. Res. Vet.
Sci. 7:394.

Netke, S.P., K.E. Gardner, and K.A. Kendall. 1960. Physiological
responses of dairy calves to certain carbohydrates when
added to a milk replacer diet. J. Dairy Sci. 43:892.

Netke, S.P., K.E. Gardner, and K.A. Kendall. 1962. Effect of diet
pH on fecal consistency of young calves. J. Dairy Sci.
45:105.

Nitsan, Z.R., R. Volcani, S. Gordin, and A. Hasdai. 1971. Growth and
nutrient utilization by calves fed milk replacers containing
milk or soybean protein concentrate toasted to various degrees.
J. Dairy Sci. 54:1294.

Nitsan, Z.R., R. Volcani, A. Hasdai, and S. Gordin. 1972. Soybean
protein substitute for milk protein in milk replacers for
suckling calves. J. Dairy Sci. 55:811.

Noller, C.H., G.M. Ward, A.D. McGilliard, D.F. Huffman, and C.W. Duncan.
1956. The effect of age of the calf on the availability of
nutrients in vegetable milk-replacer rations. J. Dairy Sci.
39:1288.

116

Norris, L.C. 1925. The production of volatile fatty acids in the
intestinal tract of calves fed whole milk or cereal gruel.
New York (Cornell) Exp. Sta., Memoir 90.

O'Dell, B.L. 1969. Effect of dietary components upon zinc availa-
bility. Am. J. Clin. Nutrition 22:1315.

Okamoto, M., J.W. Thomas, and T.L. JOhnson. 1959. Utilization of
various carbohydrates by young calves. J. Dairy Sci. 42:920.

Owen, F.G., and C.J. Brown. 1958. Interrelationship of milk temperature,
dilution and curd formation in the response of calves to whole
diets. J. Dairy Sci. 41:1534.

¢rskov, O.R. 1982. Protein Nutrition in Ruminant. p. 11. Academic
Press, New York, NY.

¢rskov, E.R., D. Benzie, and R.N.B. Kay. 1970. The effect of feeding
procedure on closure of the oesophageal groove in young sheep.
Br. J. Nutr. 24:785.

Paganelli, R., R.J. Levinsky, J. Brostoff, and D.G. Wraith. 1979.
Immune complexes containing food proteins in normal and atopic
subjects after oral challenge and effect of sodium cromoglycate
on antigen absorption. Lancet i:1270.

Paruelle, J.L., R. Toullec, J.F. Frantzen, and C.M. Mathieu. 1972.
Utilisation du proteines per 1e veau preruminant a l'engrais.
Annls. Zootech. 21:319.

Patton, R.S., P.T. Chandler, and O.G. Gonzalez. 1975. Nutritive
values of crab meal for young ruminanting calves. J. Dairy
Sci. 58:404.

Pedersen, V.B., and B. Foltmann. 1973. The amino acid sequence of
the first 61 residues of chymosin (Rennin E.C. 3.4.4.3).
Fed. Exp. Biol. Soc. Letters 35:250.

Pejic, N., and M. Kay. 1979. Soya flour in milk replacers for young
calves. Anim. Prod. 28:420.

Pelletier, G., and J. Dunnigan. 1983. Effects of administration of
glucocorticoids on pancreas and growth of dairy calves.
J. Dairy Sci. 66:1329.

Perkkia, M., E. Savilahti, and P. Kuitunen. 1981. Morphometric and
imunohistochemical study of jejunal biopsies from children
with intestinal soy allergy. Eur. J. Pedriatr. 137:63.

Phillipson, A.T., and J.E. Storry. 1965. The absorption of calcium
and magnesium from the rumen and small intestine of the sheep.
J. Physiol. 181:130.

117

Picken, J.C., H.M. Biester, and C.M. Covalut. 1952. Trickloroethane
extracted soybean oil meal poisoning. Iowa State Coll. Vet.
14:137.

Polzin, R.W., D.E. Otterby, J.M. Murphy, and J.B. Williams. 1976.
Crude casein and meat solubles in milk replacers. J. Dairy
Sci. 59:1842.

Porter, J.W.G. 1969. Digestion in the preruminant animal. Proc.
Nutr. Soc. 28:115.

Porter, J.W.G., and W.B. Hill. 1964. Nitrogen balance trials with
calves given synthetic milk diets. Nat. Inst. Res. Dairying
Ann. Rept., p. 124.

Radostits, O.M. 1975. Treatment and control of neonatal diarrhea
in calves. J. Dairy Sci. 58:464.

Radostits, C.M., and J.M. Bell. 1970. Nutrition of the pre-ruminant
dairy calf with special reference to the digestion and
absorption of nutrients: A Review. Can. J. Anim. Sci. 50:405.

Ramsey, H.A., and T.R. Willard. 1975. Soy protein for milk replacers.
J. Dairy Sci. 58:436.

Raven, A.M. 1972. Nutritional effects of including different levels
and sources of protein in milk replacers for calves. J. Sci.
Food Agr. 23:517.

Raven, A.M., and K.L. Robinson. 1965. Studies of the effect of
processing and of enzyme supplementation on the utilization
of maize in calf milk replacers. Record Agr. Res. 13:117.

Raymond, M.N., E. Bricas, R. Salasse, J. Garnier, P. Garnot, and
B.R. Dumas. 1973. A proteolytic unit for chymosin (rennin)
activity based on a reference synthetic peptide. J. Dairy
Sci. 56:419.

Roberts, M.C. 1974. The D(+)xylose absorption test in the horse.
Equine Vet. Journal 6:28.

Roy, J.H.B. 1969. Diarrhea of nutritional origin. Proc. Nutr. Soc.
28:160.

Roy, J.H.B. 1974. Problems in the nutrition of the preruminant calf.
Proc. Nutr. Soc. 33:79.

Roy, J.H.B. 1980. The Calf. Butterworth & Co., Ltd., London.

Roy, J.H.B., and I.J.F. Stobo. 1975. Nutrition of the preruminant
calf. In: Digestion and metabolism in the ruminant.

118

I.W. MacDonald and A.C.I. Warner, editors. The University of
New England Publishing Unit, Armidale, N.S.W. Australia.

Roy, J.H.B., I.J.F. Stobo, S.M. Shotton, P. Ganderton, and C.M. Gillies.
1977. The nutritive values of non-milk proteins for the
pre-ruminating calf. The effect of replacement of milk
protein by soya—bean or fish-protein concentrate. Brit. J.
Nutr. 38:167.

Rupel, I.W., and K.O. Wilson. 1962. De—fatted fish meal as an ingre-
dient in milk replacers for young calves. Texas Agr. Exp.
Sta. Feed Service Rept. No. 24.

Sambeth, W., M.C. Neisheim, and J.A. Serajin. 1967. Separation of
soybean whey into fractions with different biological
activities for chicks and rats. J. Nutr. 92:479.

Sanford, P.A. 1982. Digestive System Physiology. Edward Arnold
Ltd., London.

Schingoethe, D., A.D.L. Gorrill, J.W. Thomas, and J. Yang. 1970.
Size and proteolytic enzyme activity of the pancreas of
several species of vertebrate animals. Can. J. Physiol.
Pharmacol. 48:43.

Schugel, L.M. 1973. Nutrition of the baby calf. Proc. 6th Ann.
Conf. Amer. Assoc. Bovine Pract., p. 82.

Schultze, M.C., P. Klubes, V. Perman, N.S. Mizumo, F.W. Bates, and
J.W. Sautter. 1959. Blood dyscrasia in calves induced by
S-(dichlorovinyl)-L-cysteine. Blood 14:1015.

Seegraber, F.J., and J.L. Morrill. 1979. Effect of soy protein on
intestinal absorptive ability of calves by the xylose
absorption test. J. Dairy Sci. 62:972.

Seegraber, F.J., and J.L. Morrill. ~1982a. Effect of protein source
on morphology and absorptive ability of calf small intestine.
J. Dairy Sci. 65(Supp1. 1):129.

Seegraber, F.J., and J.L. Morrill. 1982b. Effect of soy protein on
calves intestinal absorptive ability and morphology determined
by scanning electron microscopy. J. Dairy Sci. 65:1962.

Segal, S., J.B. wyngaarden, and J. Foley. 1957. The effect of
insulin on blood levels of infused pentoses in man. J. Clin.
Invest. 36:1383.

Seoane, J.R., A.D.L. Gorrill, L. Crampton, J.D. Jones, T.M. MacIntyre,
J.W.G. Nicholson, and R.G. Stevenson. 1976. Low-glucosinolate,
low-erucid acid full—fat rapeseed (cv.Tower) as a protein and
energy source in lamb milk replacers. Can. J. Anim. Sci. 56:393.

119

Shaw, R.H., T.E. Woodward, and R.P. Norton. 1918. Digestion of
starch by the young calf. J. Agr. Res. 12:575.

Siddons, R.C., R.H. Smith, M.J. Hendschel, W.B. Hill, and J.W.G.
Porter. 1969. Carbohydrate utilization in the pre-ruminant
calf. Br. J. Nutr. 23:333.

Sissons, J.W., and R.H. Smith. 1976. The effect of different diets
including those containing soya-bean products, on digesta
movement and water and nitrogen absorption in the small
intestine of the pre-ruminant calf. Br. J. Nutr. 36:421.

Sissons, J.W., R.H. Smith, and D. Hewitt. 1979. The effect of giving
feeds containing soya-bean meal treated or extracted with
ethanol on digestive processes in the preruminant calf.

Br. J. Nutr. 42:477.

Sleiman, F.T., and J.T. Huber. 1971. Fish protein concentrate and
whey protein in milk replacer diets. J. Anim. Sci. 33:1170
(abstr).

Smith, R.H. 1962. Net exchange of certain inorganic ions and water
in the alimentary tract of the milk fed calf. Biochem. J.
83:151.

Smith, R.H., W.B. Hill, and J.W. Sissons. 1970. The effect of diets
containing soya products on the passage of digesta through
the alimentary tract of the preruminant calf. Proc. Nutr.
Soc. 29:2A.

Smith,

50

.H., and J.W. Sissons. 11975. The effect of different feeds,
including those containing soya-bean products, on the passage
of digesta from the abomasum of the preruminant calf. Brit.
J. Nutr. 33:329.

Smith, R.H., and C.F. wynn. 1971. Effects of feeding soya products
to preruminant calves. Proc. Nutr. Soc. 30:75A.

Sudweeks, B.M., and H.A. Ramsey. 1972. Growth of calves fed milk
replacers prepared from different fractions of fully-cooked
soy flour. J. Dairy Sci. 55:705(abstr).

Tagari, H., and J.H.B. Roy. 1969. The effect of heat treatment on
the nutritive value of milk for the young calf. 8. The effect
of the pre-heating treatment of spray-dried skimmilk on the pH
and the contents of total protein and nonprotein nitrogen of
the pyloric outflow. Br. J. Nutr. 23:763.

Taylor, T.G. V1965. The availability of the calcium and phosphorus
of plant material for animals. Proc. Nutr. Soc. 24:105.

120

Taylor, R.E. 1962. Pancreatic secretion in the sheep. Res. Vet.
Sci. 3:63.

Ternouth, J.H., and J.H.B. Roy. 1973. The effect of diet and feeding
technique on digestive function in the calf. Ann. Rech.
Veter. 4:19.

Ternouth, J.H., J.H.B. Roy, and S.M. Shotton. 1976. Concurrent
studies of the flow of digesta in the duodenum and of
exocrine pancreatic secretion of calves. 4. The effect
of age. Br. J. Nutr. 36:523.

Ternouth, J.H., J.H.B. Roy, and R.C. Siddons. 1974. Concurrent
studies on the flow of digesta in the duodenum and of
exocrine pancreatic secretion of calves. 2. The effects
of addition of fat to skimmilk and of "severe" pre—heating
treatment of spray-dried skimmilk powder. Br. J. Nutr. 31:13.

Ternouth, J.H., J.H.B. Roy, I.J.F. Stobo, S.M. Shotton, and C.M.
Gillies. 1977. Concurrent studies of the flow of digesta in
the duodenum and of exocrine pancreatic secretion in calves.
5. The effect of giving milk once and twice daily, and of
weaning. Br. J. Nutr. 37:237.

Ternouth, J.H., R.C. Siddons, and J. Toothill. 1971. Pancreatic
secretion in the milk fed calf. Proc. Nutr. Soc. 30:89A.

Ternouth, J.H., S.Y. Thompson, and J. Edwards-Webb. 1980. Concurrent
studies of the flow of digesta in the duodenum and of exocrine
pancreatic secretion of calves. 7. Influence of milk sub-
stitutes on abomasal lipolysis and salivary secretion.

Br. J. Nutr. 44:141.

Ternouth, J.H., J.H.B. Roy, S.Y. Thompson, J. Toothill, C.M. Gillies,
and J.D. Edwards-webb. 1975. Concurrent studies of the flow
of digesta in the duodenum and exocrine pancreatic secretion
of calves. 3. Further studies on the addition of fat to
skimmilk and the use of non-milk proteins in milk substitute
diets. Br. J. Nutr. 33:181.

Thivend, P., C.F.S. Clarlk, E.R. ¢rskov, and R.N.B. Kay. 1979.
Digestion of partially hydrolyzed starch in milk replacers
by the young lamb. Ann. Rech. Vet. 10:422.

Thivend, P., R. Toullec, and P. Guilloteau. 1980. Digestive
adaptation in the preruminant. In: Digestive Physiology
and Metabolism in Ruminants, p. 561. AVI Publishing Company,
Inc., Westpoint, Connecticut.

Thomas, J.E. 1967. Neural regulation of pancreatic secretion. In:
Handbook of Physiology 2:955. Amer. Physiol. Soc., Williams
and Wilkins Co.

121

Thomas, H.C., and D.M.V. Parrott. 1974. The induction of tolerance
to a soluble protein antigen by oral administration.
Immunology 27:631.

Thompson, D.B., and J.W. Erdman, Jr. 1984. The effect of soy protein
isolate in the diet on retention by the rat of iron from
radiolabeled test meals. J. Nutr. 114:307.

Thompson, R.M., M.L. Kakade, W.E. Engelstad, M.A. Fowler, and F.
Friedrich. 1974. Nutritive value of soybean for calves.
J. Dairy Sci. 57:651 (abstr).

Topps, J.H., R.N.B. Kay, and E.D. Goodall. 1968. Digestion of
concentrate and of hay diets in the stomach and intestines
of ruminants. 1. Sheep. Brit. J. Nutr. 22:261.

Toullec, R., and C.M. Mathieu. -1973. Influence de la composition
du lait ingere sur la vidange stomocale chez le veau
preruminant. Annals. Rech. Veter. 4:13.

Track, N.S., and M. Bokermann. 1973. Functional development of the
bovine exocrine pancreas. Comp. Biochem. Physiol. 44:1101.

Wadleigh, J.A., and D.N. Mowat. 1978. Nipple feeding of two types
of protein supplements to calves. Can. J. Anim. Sci. 58:385.

Walker, W.A. 1976. Host defense mechanisms in the gastro-intestinal
tract. Pediatrics 57:901.

Walker, W.A., and K.J. Isselbacher. 1974. Uptake and transport of
macromolecules by the intestine. Possible role in clinical
disorders. Gastroenterology 67:531.

wallace, G.M., W.R. Bannatyne, and A. Khaleque. 1971. Studies on the
processing and properties of soy milk. II. Effect of proces-
sing conditions on the trypsin inhibitor activity and the
digestibility "in vitro" of proteins in various soy milk
preparations. J. Sci. Food Agric. 22:256.

Weijers, H.A., and J.H. van de Kamer. 1965. Alteration of intestinal
bacterial flora as a cause of diarrhea. Nutr. Abstr. Rev.
35:591.

Wendlandt, R.M., K.E. Harshbarger, and R.D. Genskow. 1968. Growth
response of calves fed milk replacers containing fish meal.
J. Dairy Sci. 51:972 (abstr).

White, A.A., and W.C. Hess. 1956. Paper chromatographic detection of
sugars in normal and dystrophic human urines. Arch. Biochem.
64:57.

122

Willard, T.R., and H.A. Ramsey. 1972. Effect of treating soy flour
with anhydrous hydrogen chloride on its value as a milk
replacer ingredient for calves. J. Dairy Sci. 55:704 (abstr).

Williams, A.P., and R.H. Smith. 1973. Factors affecting free amino
acid and urea nitrogen concentrations in the blood plasma of
preruminant calves. Proc. Nutr. Soc. 32:51A.

Williams, A.P., and R.H. Smith. 1974a. Concentrations of amino acids
and urea in the plasma of the ruminanting calf and estimation
of the amino acid requirements. Br. J. Nutr. 32:421.

Williams, A.P., and R.H. Smith. 1974b. Factors affecting free amino
acid and urea nitrogen concentration in the blood plasma of
ruminanting calves. Proc. Nutr. Soc. 33:34A.

Williams, A.P., and R.H. Smith. 1975. Concentrations of amino acids
and urea in the plasma of the preruminant calf and estimation
of the amino acid requirements. Br. J. Nutr. 33:149.

Williams, J.B., and C.B. Knodt. 1951. The supplementation of milk
replacements with enzymes and other products. J. Anim. Sci.
10:975.

Williams, J.B., and J.W. Rust. 1968. Study shows fish flour can be
used in milk replacers. Feedstuffs 40:56.

Williams, V.J., J.H.B. Roy, and C.M. Gillies. 1976. Milk-substitute
dietcomposition and abomasal secretion in the calf. Br. J.
Nutr. 36:317.

Wise, G.H., and G.W. Anderson. 1939. Factors affecting passage of
liquids into the rumen of the dairy calf. 1. Method of
administering liquids-drinking from an open pail vs.
through a rubber nipple. J. Dairy Sci. 22:697.

Wittenberg, K.M., and J.R. Ingalls. 1979. Utilization of fababean
protein concentrate in milk substitute diets by preruminant
calves. J. Dairy Sci. 62:1626.

wyngaarden, J.B., S. Segal, and J.B. Foley. 1957. Physiological
disposition and metabolic fate of infused pentoses in man.
J. Clin. Investigation 36:1395.