SOME FACTORS INFLUENCING THE PERCENTAGE OF NON-RETURNS
OF DAIRY BULLS IN’ ARTIFICIAL BREEDING

By

Bhalchandra. Tanaji Sangle

A THESIS

Submitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Dairy

1953

SOME FACTORS INFLUENCING THE PERCENTAGE OF NON-RETURNS
OF DAIRY BULLS IN ARTIFICIAL BREEDING

■B y
' Bhalcliandra Tanaji Sangle

AN ABSTRACT

Submitted to the School of Graduate Studies of Michigan
State College of Agriculture and Applied Science
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Dairy

Year 1953

Approved

Bhalchandra Tanaji Sangle

THESIS ABSTRACT

The breeding and semen collection records of bulls belonging to
Michigan /artificial Breeders Association were analyzed for a period of
about a year in order to study some of the factors influencing the per­
centage of non-returns.

The factors studied were age of semen, bull,

breed, month and season of breeding, registered and non-registered
females .
The data were compiled by IBM machines and analyzed yielding follow­
ing results:
In general, the yearly percent of non-returns for bulls and for
breeds declined as age of semen advanced from 1 to 5 days . Hence semen
should be used as fresh as possible .
Bulls as well as breeds varied widely in the decline of percent of
non-returns for day-to-day storage of seme", from 1 to 5 days.
The over-a.ll yearly percent of non-returns was the highest for Angus
and was the lowest for Red Dane breed.

Holstein ranked 2nd whereas

Jersey ranked 3rd to Angus in percent of non-returns.

The over-all yearly percentages of non-returns for dairy bulls for
1 , 2 , 3,

5 -day-old semen were 69.59 , 63.05 , 56.20 , 51.5U and 5 0 .81|
.

percent, respectively.
In Red Dane, the percent of total services for 1-day-old semen was
markedly low compared to other breeds.

-1-

Bhalchandra Tanaji Sangle

The percent of non-returns was lowest in May for Holstein.

It was

lowest in August for Guernsey, Jersey and Red Dane, whereas for Angus,
it was lowest in September.
For all dairy breeds, the percent of non-returns was the highest in
fall whereas it was highest in spring for Angus.

For Holstein and Red

Dane, the percent of non-returns was the lowest in winter whereas for
Guernsey and Jersey, it was lowest in summer.
The weighted average of percent of non-returns with 1-day-old semen
was 1 0 .9$ greater in 1st service registered females than 1st service non­
registered females .
The number of females inseminated with a day's collection of semen
for a bull was the highest in Holstein breed.
Concentra.tion of semen was the highest in Jersey breed.

Semen volume,

sperm concentration, percentage of sperms alive in non-stored semen and
progressive motility of sperms in non-stored semen were liigher in dairy
bulls than the Angus bulls. However, the raw semen movement was lower
than Angus bulls.
A highly significant positive correlation was found between raw semen
movement and progressive motility of sperms in non-stored semen (r=+0 .1ii65) .
A liighly significant (l$ level) positive correlation was noted be­
tween each of the following semen characteristics and percent of nonre turns:
Raw semen movement (r = +0.195)
Percentage of sperms alive in li-day-old re-examined semen (r = +0.1262)

-2-

Bhalchandra Tanaji Sangle

Concentration of sperm per 1/1000 cubic m m . of diluted semen
(r = +0.1213)
Progressive motility of sperms in non-stored semen (r = +O.O88I4.)
Observations on progressive motility of sperms either in 3-day or
in it-day-old re-examined semen seem to be of very little use in predict­
ing the percent of non-returns.

-3-

VITA

Bhalchandra Tana.ji Sangle
Candidate for the degree of
Doctor of Philosophy

Final examination, July 2 h , 1953, 10:00 A. M ., Room 213, Dairy Building

Dissertation:

Some Factors Influencing the Percentage of Non-returns
of Dairy Bulls in Artificial Breeding

Outline of Studies:
Major subject: Dairy Production
Minor subjects: Animal Physiology, Animal Nutrition

Biographical Items
Born, August 29, 1925, Dhulia., Bombay State, India
Undergraduate studies, College of Agriculture, Poona,
I9I4.5-I48
Graduate Studies, Michigan State College, 19U9-53
Experience:
Captain of Inter-collegiate Kho-Kho Team
College of Agriculture, Poona, Bombay State
19U7-U8
Agricultural Officer, Crop Breeding Station,
Shahada, Bombay State 19hQ-h9
Member of The American Dairy Science Association

AC KNOWLSD CMENT S

The -writer wishes to express his sincere
Dr. N. P. Ralston, Professor of Dairying, for
failing interest and encouragement during the
gation and for his assistance in the critical
this manuscript.

feelings of gratitude to
his valuable guidance, un­
course of tliis investi­
reading and preparation of

The author is greatly indebted to the Government of Bombay for the
award of scholarship and to the Scholarship Board, Michigan State College,
for the award of Alumni Predoctoral Fellowship which, made it possible for
him to continue his study for the advanced degrees . Grateful acknowledg­
ment is also d.ue to Dr. Earl Weaver, Head of Dairy Department, Michigan
State College and to Mr. A. C. Baltzer, Secretary and Treasurer of
Michigan Artificial. Breeders Cooperative, Inc., East Lansing, for the
allotment of funds in order to carry out the present investigation.
The author deeply appreciates the help of Mr. A. C. Baltzer, for
the availability of the semen collection and breeding records of Michigan
Artificial Breeders Association. Sincere appreciation is also expressed
to Mr. R. W. Green, Research Assistant, Michigan Artificial Breeders
Association, and to Mr. Fred. Dombroske, Plant Manager, Michigan Artificial
Breeders Association, and to Messrs Robert Wheelock and Cliris Hebden of
Michigan Artificial Breeders Association for their helpful suggestions
and assistance in acquainting with some of the data on semen collection
and breeding. The author is highly obliged to Miss Norma Taschner,
Assistant Superintendent, Tabulating Department, for her kind help in
punching and compilation of semen collection and breeding records by IBM
machines. Sincere thanks are extended to Dr. W. D. Ba.ten for his kind
assistance in statistical analysis and to Miss Frances R. Allen, dairy
extension department, for supplying the census figures regarding the
percentage of cows bred artificially during the past few years on
M ic higan f arm s .
The writer is very grateful to Dr. C. F. Huffman, Dr. E. P. Reineke,
Dr. C. A. Hoppert, Dr. C. R. Megee and to Dr. A. C. Groschke for helpful
suggestions, assistance and encouragement throughout his advanced train­
ing in tliis great institution of agriculture and applied science.

TABLE OF CONTENTS
PAGE
INTRODUCTION..........................................................

1

GENERAL OBJECTIVES....................................................

I,

MATERIALS AND METHODS U S E D ...........................................

5

(A)
(B)
(C)
(D)
(E)
(F)

Collection of Semen .........................................
Examination of Semen (Techniques, Ra.tings, etc.)..........
Dilution a.nd Storage of S e m e n ..............................
Shipment of Sem e n ...........................................
Re-examination of Diluted Stored S e m e n ....................
Preparation of Egg-Yolk Citrate Diluter.............

5
3
8
9
10
11

GENERAL INVESTIGATIONAL PROCEDURE....................................

12

(A) Source of D a t a ..............................................
(B) Placing Da.ta on IBM C a r d s ..................................
(C) Compilation of Data, from IBM Cards (Standard Card Nos. 1
and 2) for:
(a.) Calculation of percent of non-returns...........
(b) Correlation between semen characteristics.......
(c) Correlation of semen characteristics and percent
of non-returns.......

12
13

SOME OF THE FACTORS INFLUENCING PERCENT OF NON-RETURNS OR RATE OF
CONCEPTION.......................................................
(A) Review of Literature........................................
(a) Age of semen in relation to percent of non­
returns ............................................
(b) Relative fertility of b u l l .......................
(c) Relative fertility of cow a.nd cow families.......
(d) Breed of animal...................................
(e) Health of animal..................................
(f) Age of animal.....................................
(g) Month and season of b r e e d i n g ....................
(h) Time of insemination in relation to time of
ovulation..........................................
(i) Time of breeding after calving...................
(j) Skill and experience of technicians and insemina.tors.............................................

16
16
21
21

22
22
22
26
27
27
28
28
30

3b
33
36

TABLE OF CONTENTS - Continued

PAGE

(k) Herd m a n a g e m e n t ..............
(l) Breeding efficiency b y artificial v s . natural
m e t h o d ..............................................
(B)
(c)
(D)
(E)

Experimental Proced u r e.....................................
R e s u l t s .......
D iscussion...................
Summary and Conclusions.......

INTER-RELATIONSHIP OF CERTAIN SEMEN CHARACTERISTICS AND RELATION­
SHIP BETWEEN VARIOUS SEMEN CHARACTERISTICS AND P E R C M T OF N O N ­
RETURNS ...........................................................
(A)
(B)
(c)
(D)
(E)

36
37
38
1;0
61
68

72

Review of Literature........................................
Experimental Proced u r e......................................
R e s u l t s ......................................................
Discussion...................................................
Summary and Conclus i o n s .....................................

72
77
80
86
90

LITERATURE C I T E D .......................................................

9h

1

INTRODUCTION

Dairy cattle breeding is one of the mai n tools for the improvement
in the performance of a d a i r y herd.
improvement depending on the

It can either "make or* mar" the

ability in the selection of the sires .

Judicious selection of the b u l l s , therefore, is very important.
it is rather a diff i c u l t t a s k

However,

a.s it requires a. trained personnel having

a. good knowledge

of genetics

gram, therefore,

is less l i k e l y to be within the reach of an average

dairymen unless lie resorts to
experts in cattle

a.nd animal breeding.

A sound breeding pro­

artificial insemination.

This is because

breeding are concerned with the selection of superior

sires for the a rtificial b r e e d i n g association.
A constantly growing, increased interest for the use of artificial
insemination has been demo n s t r a t e d by Miciiigan dairymen over the past
number of years .

Tliis can b e easily seen from the reports of the

Michigan Agricultural S tatisti c s

(1951), Michigan Cooperative Crop Report­

ing Service (1953) . and from Annual Report of Mr. A. C. Baltzer (19511952).

According; to these reports, 6 percent of the total number of cows

(2 years old and over) on M i c h i g a n farms were bred artificially in the
year 19^6; 12.7 p e r c e n t i n 1 9 ^ 8 5 ll|.8 percent in 19U9; 17.1 percent In
1950; 20.5 percent in 1951 and 22.3 percent in the year 1952.
About 90 p e r c e n t of the dairymen In Michigan could have a fairly
rapid and substantial genetic
they would use t h e

improvement in their dairy herds if only

superior inheritance that is provided for them by

2

Michigan Artificial Breeders Cooperative, Incorporated.

Dairymen are

becoming more conscious of the fact that artificial insemination does
possess great potentialities for great improvement through the use of
outstanding sires which few dairymen could afford to own.

Artificial

insemination is now considered to be the cheapest and easiest way of
introducing the desired inheritance in the average quality herd in
Michigan.
In order that the artificial breeding program be a success not only
the proper selection of bulls for high production and good type is
essential but also bulls that produce high quality semen which will stand
up during processing, shipping and insemination, thus resulting in a high
conception rate .

Equally important is the quality of the inseminator-

technicians and the use of the best techniques of insemination.

The herd

owner also has a major role to play in the success of artificial breeders
cooperatives. Besides good breeding, he must be conscious of many factors
such as proper feeding (.nutrition) , efficient management and disease
control which are responsible for getting a high conception rate in his
herd.
Educational programs beamed at the men working in the stud, the
inseminators working in the field, the individual herd owners, and the
agricultural public service personnel are important and must be maintained
with a great deal of enthusiasm and finesse.

The most efficient teaching

is tirrough the use of current local personal information to demonstrate
the proper and improper techniques, methods and procedures.

B y con­

stantly developing a program through different approaches by compiling,

3

analyzing and interpreting the -work of the organization, the mora l e .and
ehthusiasm of the personnel can be maintained.

This also favors the

development of new ideas for more efficient methods and ways of bring­
ing the latest information about the details of operation that are so
important if high conception rates are to be obtained tlirough artificial
insemination.

GENERAL OBJECTIVES

The objectives of this investigation are:
I. To study some of the factors which may influence percent of
non-returns:
(A) Age of semen
(B) Bull
(C) Breed
(D) Month and Season of year
(E) Registered and non-registered females
II. To study the inter-relationship of certain semen characteristics
and relationship between vario-as semen characteristics and per­
cent of non-returns.

5

MATERIALS AND METHODS USED

The data used in this investigation were taken from the records
kept at the Michigan Artificial Breeders Cooperative, Incorporated, East
Lansing.

In 195>l-5>2 the Michigan Artificial Breeders Association con­

sisted of IJ4.I4 local organizations located tliroughout the State of
Michigan.
Lansing.

The bull stud is located at the central headquarters in Ea.st
The semen was collected from bulls representing 9 breeds.

Of the 5 breeds, b were of dairy type (Holstein, Guernsey, Jersey, lied
Dane) and one vias of beef type (Angus) .

(A) Collection of Semen
In the majority of cases, semen was collected from each bull at an
interval of 6 or 8 days.

The eja.culaies (semen) collected a.t less than

5 days apart from a bull is not included in the present investigation.
This is because of the fact that the current services resulting from each
of these ejaculates cannot be completely separated by the procedure used
in tliis study for determining the percent of non-returns .

The collection

of semen with very few exceptions, was made at night every day, except
Saturday, starting from about 9 p.m. to about 12 midnight.

Semen was

collected by means of an artificial vagina.

(B) Examination of Semen (techniques, ratings, etc.)
Immediately after collection, the semen samples were examined in
the laboratory by trained, experienced personnel, for the following sernen
characteristics:

6

Volume of semen:

It was measured to the nearest 0.1 ml. by-

means of a graduated measuring cylinder.

Haw semen movements

It was determined by examining a drop of

undiluted fresh semen under a microscope by using 100 magnifi­
cation.

An appropriate rating for movement of raw semen de­

pending on the vigor of movement of the sperm mass was
estimated as follows:
Estimated Value
for the Rating

Hating

Explanation of the Rating

+
/ or M

Maximum raw semen movement
Intermediate raw semen movement
Very little or no raw semen
movement

90 percent
70 percent
0 percent

No semen sample was discarded on the basis of raw semen move­
ment alone even though the sample had - rating for raw semen
movement.

Concentration of semen:

It was determined by a photelometer

as described by Willett and Buckner.

One-tenth ml. of undi­

luted fresh semen was mixed thorouglily with U ml. of 3.2
percent sodium citrate (Na3C 6H 507 .2Ha0) in the glass cylindri­
cal absorption cell (vial) and the photelometer reading was
taken.

The reading was then converted into concentration

(number of spermatozoa per cubic mm. of undiluted semen) after
referring to a standard table.

Semen samples showing less than

500,000 spermatozoa per cubic mm. of undiluted semen were not
sent for insemination and hence could not be included in the
present investigation.

7

Progressive motility of sperms:

A drop of fresh semen diluted

with egg-yolk citrate buffer was examined under a microscope
using a magnification of U O O .

An appropriate rating for pro­

gressive m o t i l i t y of sperms depending on the nature of forward
movement (fast or sluggish) of live-sperms in the semen sample
was estimated as follows:
Rating
E
VG
G+
G

Explanation of the Rating

Estimated Value
for the Rating

Excellent progressive motility
of sperms
Very good progressive motility
of sperms
Good plus progressive motility
of sperms
Good progressive motility of
sperms

90
80
70
60

In very rare cases, semen samples having less than G+ rating
for progressive motility of sperms , were obtained.

Such samples

were discarded on the basis of other semen characteristics such
as percentage of sperms alive, raw semen movement and concen­
tration of semen.

Percentage of sperms alive:

A drop of fresh semen diluted with

egg-yolk citrate buffer was observed under the microscope using
a magnification of U00 and the percentage of sperms alive in
the sample was estimated as 80, 75, 70 etc.

Semen samples with

a percentage of live-sperms less than 70 were usually dis­
carded and hence could not be included in the present investi­
gation.

jsS M

a

Wien the semen obtained during the first ejaculation from a bull
was small in volume, a second ejaculate was collected subsequently from
the same bull.

The first and second ejaculates (non-stored semen) were

examined separately for volume of semen, raw semen movement, concentra.tion of sperm, progressive motility of spermatozoa, and percentage of
sperms alive.

After examination, the two ejaculates were mixed together

for insemination.

However, the number of mixed ejaculates was small.

In the present study, whenever two ejaculates from a bull were mixed,
weighted averages for ra.w semen movement, concentration of semen, pro­
gressive motility of sperms and percentage of live-sperms were calculated
on the basis of semen volume -used for dilution.

The weighted averages

thus obtained represent the ratings for various semen characteristics of
the mixed semen.

In the ca.se of volume of semen, the arithmetic average

of the volume of two ejaculates was talcen to represent the volume of
mixed ejaculate.
In some cases, the first ejaculate from bulls was lost and hence the
second ejaculate from the same bull was collected subsequently.

(C) Dilution and Stora.ge of Semen
While a. portion of the semen sample was being examined microscopically,
the remaining portion contained in a glass tube was placed in warm water
at about 90° F.

If the semen sample wa.s found to meet the minimum r e ­

quirements of semen characteristics or combination of seme

characteristics

such as percentage of sperms alive, progressive motility of sperm, raw*
semen movement and concentration of semen (characteristics listed in order

9

of importance for judgment) , it was poured into 59 ml. of egg-;/olk
citrate diluter previously wanned to 90° F.

The diluted semen was then

placed in a refrigera.tor and cooled on the average not faster than 1
per minute to kO

o

F.

F . More diluter at 1|0° F . was then added to the

original 59 m l . dilution making up a total volume of diluted semen on
each bull according to the sernen needs for a particular day *s collection.
About 3 to

ml. of diluted semen was stored in the refrigerator at j.j.0O F.

in order to re-examine on the 3rd and/or Uth day of storage for progressive
motility of sperms and percentage of sperms alive.
diluted semen was poured into 8 ml. gla.ss vials.

The remaining, fresh,
The vials were plugged

with a cork stopper and the top of the vial along with the stopper was
paraffined.

(D) Shipment of Semen
1. Parcel post shipment:

Glass vials containing diluted semen

were placed in a hollow tin can with a. jacket containing ice.
The can was wrapped in an insulated ba.g which was then packed
for shipment by parcel post.

The semen was in transit from

16 to 2l| hours at about hO° F . and was received by insemina.tors
after about 12 to 35 hours from the time of collection,

however,

the majority of the inseminators received the semen about 3b
hours from the time of collection.
2 . Airplane shipment of semen;

Glass vials containing diluted

semen were wrapped in several thicknesses of paper and were
placed in the insulated bag in contact with a tin can enclosing
ice.

The bag was then packed in a cardboard box for shipment

10

by airplane . The semen was in transit from 0 to 5 hours at
about I|0° F. and was received by the inserninators after 11 to
16 hours (on an average 1 3 /^ hours) from the time of semen
collection.
Semen received by the inserninators either by parcel post or by air­
plane delivery, was kept in a refrigerator at about U0° F. until used.
The semen was carried to the farms for insemination in a thermos bottle
or ice chest at temperature of about I4.O

F.

(E) Re-examination of the diluted stored semen.
Semen samples stored in a refrigerator at J4O0 F . were re-examined
under a microscope (UOO magnification) for progressive motility of sperms
and percentage of live sperms on the 3rd and/or Uth day of storage.

An

appropriate rating for progressive motility of sperms depending on the
nature of forward movement (fast or sluggish) of live-sperms was estimated
as follows:
Progressive Motility of Sperms
Rating
G+
G
GF+
F
FP
Dead

Explanation of the Rating
Good plus progressive motility of sperms
Good progressive motility of sperms
Good minus progressive motility of sperms
Fair plus progressive motility of sperms
Fair progressive motility of sperms
Fair minus progressive motility of sperms
Poor progressive motility of sperms
iMo progressive motility of sperms

Percentage of sperms alive:
etc .

Estimated Value
for the Rating
70
60
50
I4.O
30
20
10
0

It was estimated as 60, 55, 50, h p ,

11

PreP ara^:j-on of Egg-Yolk citrate diluter:
The egg-yolk citrate diluter was made up of 1 part of egg-yolk to
1 part of citrate buffer.

To this egg-yolk citrate mixture, 500 m g m s .

of crystalline dihydro-streptomycin (Merck) and 500,000 units of
crystalline penicillin (Merck) were added for every 1000 ml. of the mix­
ture.

The egg-yolk citrate was prepared every day except Saturday, about

8 hours before use.

The diluter was kept in a. refrigerator at i|0° F.

until it was needed for dilution.
Citrate buffer that was used for preparing the diluter was made
every week by adding 60 grams of sodium citrate (Merck)
and 2000 ml. of distilled water.

(ka3C 6H50 7 .2H30)

The citrate solution was heated in a.

pressure cooker at 212° F . for 20 minutes at 15 pounds pressure. It was
o
then cooled and stored in the refrigerator at 1|0 F . and used whenever
needed during the week.

12

GENERAL INVESTIGATIONAL PROCEDURE

(A) Source of Data
The data, on semen characteristics was taken from the semen collection
data sheets (records) of the Michigan Artificial Breeders Association and
covers the period from the semen collection date of June I, 1931 to 1-ia.y
31, 1932.

The breeding record corresponding to these ejaculates was ob­

tained from IBM cards (Standard Card No. l) punched, according to the out­
linementioned belox'i and covers the period from June 1, 1931 to

h y 1932.

Breeding

September

records were analyzed on the basis of 90 day non-returns

for 1, 2, 3 , 1|, 5 Bay old semen.

A female (cow or heifer) was assumed to

be pregnant, if she was not bred 90 days following the last service.

The

percent of non-returns was calculated on the total of first, second, third,
fourth, fifth a.nd over services to a female.

Outline of Standard Card No. 1
Columns punched

(Breeding Record)

Description

1

First service females registered or non-registered

2-U

Code number for local organization of Michigan
cial Breeders Association

3-6

Month of current service to the female

Artifi­

7-6

Day of current service to the female

9

Year of current service to the female

10-12

Code number of bull used on current service to the
female

13-ill

Service number of the female

13

15-16

Month of previous service to the female

17-18

Day of previous service to the female

19

Year of previous service to the female

20-22

Code number of bull used on previous service to the
female

23

Automatic punch o u t .

(B) Placing Data on IBM Cards
IBM cards (Standard Card No. 2) were punched showing information
from Michigan Artificial Breeders Cooperative, I n c . (MABCl) semen collection
data sheets

starting from the semen collection date of June 1,

May 31,1952.

There were some calculations made on

this card.

1951 to
The data

were punched in the columns indicated according to the following instruc­
tions:
Columns Punched
1-3

Description
Code number of bull used for semen collection; also
punch high MX" in column 1 for bulls which are used
for semen collection a.t less than 5 days apart,
(encircled by blue pencil in MABCI sernen collection
data sheets)

If.—5

The month of semen collection

6-7

The day of semen collection

8

The year of semen collection, that
1951 as 1 snd the year 1952 as 2

9

Name of the day coded as:
1 for Monday, 2 for Tuesday, 3 for Wednesday,
U for Thursday, 5 for Friday, 6 for Saturday,
7 for Sunday

10

is punch the year

Season“of semen collection coded as:
1 for fa~l 1 season which includes October, November
and December

lit
Columns Punched

Description
2 for winter season which includes January, February
and March
3 for spring season which includes April, May and
June
U for summer season which includes July, August and
September

11-13

Volume of semen in milliliters

llt-17

The concentration of semen per 1/1000 cubic milli­
meter

18-20

The dilution rate of semen, for example, 1 to 100,
punch out the latter figure of the ratio only, that
is 100

21-23

The total volume of semen after it has been diluted

2h-2$

The percentage of sperms alive in non-stored semen

26-2?

The progressive motility of sperms of non-stored
semen. Motility ratings are given in the semen
collection data sheets as E, VG, G + . G
Punch
Punch
Punch
Punch

28-29

the
the
the
the

figure 90 for
figure 80 for
figure 70 for
figure 60 for

E (Excellent)
VG (Very Good)
G+ (Good plus)
G (Good)

The raw semen movement
If there is a plus sign following the figure of
percentage of sperms alive in the non-stored semen
it means that there is maximum raw semen movement
which is estimated to be 90/.
If there is a diagonal line or letter M after the
figure of the percentage of sperms alive in the
non-stored semen it means that the raw sernen movement
is only intermediate and estimated to be 70%. If
there is a dash mark after the figure of percentage
of sperms alive in the non-stored semen, it means
that the raw semen movement is very little or none
and therefore it is estimated to be 0%
In brief, for raw semen movement punch the figure:
90 for +
70 for/or for letter M
O for -

Columns Punched

Description

30

One day old re-examined semen.

Punch out the figure 1

31-32

The progressive motility of sperms of one day old re­
examined semen.
Progressive motility ra.tings are given in the semen
collection data sheets as:
G + , G, G-, F + , F, F-, P, Dead
Punch
Punch
Punch
Punch
Punch
Punch
Punch
Punch

the figure 70 for G+ (Good plus)
the
figure 60 for G (Good)
the figure 50 for G- (Good minus)
the
figure I4O for F+ (Fair plus)
the figure 30 for F (Fair)
the figure 20 for F- (Fair minus)
the figure 10 for P (Poor)
the figure 0 for Dead

33-31

The percent of sperms alive in one day old re-examined
semen.

35

It is the three day old re-examined semen. Punch
figure 3

36-37

The progressive motility rating of sperms of the three
day old re-examined semen. Estimation (values) of
motility ratings is similar to that in the columns
31-32

38-39

The percent of sperms alive in three day old re­
examined semen

I4.O

It is the four day old re-examined semen.
figure U

Punch out

I4I-U 2

Progressive motility ratings of sperms of the four
day old re-examined semen. Estimation of progressive
motility ratings is similar to that in the columns
31-32

I4.3-I4.i4.

The percent of sperms alive in four day old re­
examined semen

15-17

The concentration of sperms per 1/1000 cubic milli­
meter of diluted semen. This can be obtained by
dividing the figures in columns 11-17 by the figures
in columns 18-20 of this same card (Standard Card #2)

16

Columns Punched

Description

U8-52

The volume of semen in milliliters squared. This
can be obtained by squaring the figures in columns
11-13 of this c a r d .

33-5>9

The concentration of raw semen per 1/1000 cubic
millimeter squared. This can be obtained by squar­
ing the figures in columns lh-17 of tills card.

60-63

The percentage of sperms alive in non-stored semen
squared. This figure can be obtained by squaring
the figures in columns 2U-25> of this card.

6U-67

The progressive motility of sperms of non-stored
semen squared. This can be obtained by squaring
the figures in columns 2o-27 of tliis card.

68-71

The movement of raw semen squared. This can be ob­
tained by squaring the figures in columns 28-29 of
this card.

72-77

The concentration of sperms per 1/1000 cubic milli­
meter of the diluted semen squared. This can be ob­
tained by squaring columns bS~b7 of this card.
(Columns 2 b-bb- These data are given (written) under
the heading of "Motility rating" in MABCI semen
collection data sheets .)
Note: Forget the sign (+ or -) before the figure of
percentage of sperms alive. For example, +70 means
that the percentage of sperms alive is 70.
Similarly,
-70 means percentage of sperms alive is 7 0 .

In the present investigation, regrouping of months into seasons
w as done as follows:
Fall season includes September, October and November
Winter season includes December, January and February
Spring season includes March, April and Ma y
Summer season includes June, July and August
1

(C) Compilation of Data, from IBM Cards (Standard Card Nos. 1 and 2) f o r :
(a) Calculation of percent of non-returns
Preparation of "Current service" summary card: -

17

Steps:(1) For each date ox semen collection (columns !*-& of Standard
Card No. 2) per bull, 5 master cards were made to represent
five consecutive dates starting from the date of semen col­
lection.

On these master cards were punched the bull code

number and the age of semen in days and the serial number .
The date of semen collection is 1-day-old semen, whereas the
next four consecutive dates represent 2 , 3 , U, 5-day old
semen, respectively.

All the master cards were sorted by

bull code number and by date of semen collection in order to
arrange them by bull and by date of semen collection
(2) All IBM cards (Standard Card No. l) having the date of current
service from June 1, 1951 to June U, 1952, were sorted by date
of current service (columns 5-9 of Standard Card No. l) and by
bull used on current service (columns 10-12 of Standard Card
No . 1 ) so as to arrange them by bull and b y date of current
service.
(3 ) IBM cards sorted in step 2 were collated with master cards
arranged as mentioned in step 1 , for two objectives:

(i) to

eliminate the current services corresponding to semen of a
bull collected at less than 5 days apart, (ii) to eliminate
the current services corresponding to two ejaculates from a
bull which were not mixed but sent to insemina.tors separately.

(U) Only the IBM cards that matched in step 3 were used to cut
'•Current service" summary cards showing the bull used on cur­
rent service and the date of current service.

Age of semen

18

in days and the serial number were then transferred from
master cards of step i, into "Current service" summary cards
after collating b y date of semen collection and bull code
number .
Preparation of
(5)

"Return service" summary card:-

All IBM cards (Standard Card No. l) having the date of previous
service from June 1, 1951 to September U, 1952, were sorted
b y date of previous service (columns 15-19 of Standard Card
No. l) and b y bull used on previous service (columns 20-22 of
Standard Card No. l) so as to arrange them by bull used on
previous service and by date of previous service.

Later, they

were collated with "Current service" summary cards mentioned
in step h for two purposes:

(i) to eliminate the breeding

record corresponding to semen of a. bull collected

at less than

5 days apart, (ii) to eliminate the breeding record correspond­
ing to two ejaculates from a bull which were not mixed but
sent to inseminators separately.
(6) Ninety-day master cards were prepared as foll o w s :A number from 1 through U62 was assigned for the date
(current service and previous service) from June 1, 1951 to
September 5-, 1952.

IBM cards were punched showing the date

of current service, the date of previous service and the
numbers assigned for the date of current service and for
the date of previotis s e r v i c e .

19

(7) IBM cards arranged by date of current service as mentioned
in step 2 were matched with 90-day master cards and the numberassigned corresponding to the date of current service was
gang-punched on ea.ch card.
(8) IBM cards matched in step 5 were further collated with 90 -day
master cards and the number assigned corresponding to date of
previous service was gang-punched on each card.
(9) The number corresponding to date of current service was sub­
tracted from the number corresponding to date of previous
service so as to get return period in d a y s .

The return period

thus obtained was punched on each IBM card (Standard Card No.
1) .

These IBM cards were then sorted by return period in

days in order to obtain 1 to 90-day returns for each bull for
each date of semen collection.

Then they were resorted by

date of previous service (columns 15-19 of Standard Card do. l)
and by bull used on previous service (columns 20-22 of Standard
Card No. l ) .

They were collated with the "Current service"

summary cards and the matching cards were used to cut the
"Return service" summary cards showing the bull used on previous
service and the date of previous service.
Preparation of "Final" summary card:(10) The "Return service" summary cards were collated with the
"Current service" summary cards and the returns were trans­
ferred to the corresponding "Current service" summary cards
so as to get "Final" summary c a r d s . The percent of non-returns

20

was calculated according to the following formula: Percent of non-returns =

Current
Returns■ y
■■ '
— services
■— ■ --Current services
JL

(11) The "Final'1 summary cards were used to arrange the breeding
data conveniently in order to study the various phases of
this investigation.

'1Fin3!” Summary Card
Columns punched
1
1*
6

-

3
5
7

8
9 - 10
11 - 12
13 — 15
16 - 18
19 — 21
22 — 2l*
25 — 27
28 — 30
31 — 32
33 — 3U
35 — 37
38 — 39
ho _ 1*1
h2 - 1*1*
1*5
U7
1*9

—
_
—

1*6
1*8
51

52

_

51*

55 - 57
58

—
61

60

Description
Bull code number
Month of semen collection
Day of semen collection
Year of semen collection
Current first services to registered females
Returns of first services to registered females
Current first services to all females
Returns of first services to all females
Percent of non-returns for first services to all
females
Current second services to all females
Returns of second services to all females
Percent of non-returns for second services to
all females
Current third services to all females
Returns of third services to all females
Percent of non-returns for third services to all
females
Current fourth services to all females
Returns of fourth services to all females
Percent of non-returns for fourth services to all
females
Current fifth and over services to all females
Returns of fifth and over services to all females
Percent of non-returns for fifth and over services
to all females
Total current services (l, 2 } 3, h , 5 and over) to
all females
Total returns for 1, 2, 3, h s 5 and over services
to all females
Percent of non-returns for total current services
(1, 2, 3, i*j 5 a-nd. over) to all females
Age of semen in days

21

62 - 6U

Percent of non-returns for first services to
registered females
Season of year
Day of week
Serial number

76
77
78-80

(b) Correlation between semen characteristics
IBM cards (Standard Card No. 2) were used to obtsin

£X'",

2.Y, 5LY3 , IE.XI and N for various semen characteristics of
Holstein, Guernsey, Jersey and Red Dane b u l l s .
(c) Correlation of semen characteristics and percent of non-returns
In view of the results reported b y Ludwick et al. (19U8) and
Erb et al. (1950)

and also because of the fact that about 83

percent of total services in the present investigation were to
first and second service females, it was decided to use the semen
samples each of which bred to forty or more females, in order to
determine the correlation of semen characteristics with percent
of non-returns.

Accordingly, the ’’Final" summary cards were

sorted on the number of total current services (1 , 2 , 3 , U, 5 ana
over service females) so as to eliminate cards (bulls) showing
less than forty total current services.
IBM cards (Standard Card No. 2) and the "Final" summary cards
having 1|0 or more total current services were collated so as to
obtain

£X,

2.X2 , S.Y, £ Y 3 , £ XY and N for each of the semen

characteristics under study.

22

SOME OF THE FACTORS INFLUENCING PERCENT OF NON-RETURNS
OR RATE OF CONCEPTION

(A)

REVIEW OF LITERATURE

(a.) Age of Semen In Relation to Percent of Non-returns
Milovanov (1932) reported that diluted semen could be stored for 6
hours w i t h good results.

According to Komara.o and Gladcinova (1937)

semen

o
may be stored successfully at temperature of 13-25 C .for 12 hours, or at
8-12°C. for 2b hours.

Hatziolos (1937) reported conception with semen

stored up to I4.8 hours.

Edwards and Walton (1938) also obtained conception

with bull semen stored for as much as 57 hours.

Altara. and Adriano (1938)

reported that the vitality of semen was unaffected after storing for 100
hours.

Kust (1939) using U 8-hour-old semen found that 60 % of cows became

pregnant.

He also noted conception in some of the cows inseminated with

72-hour and 120-liour-old semen stored at low temperatures .

Success with

stored semen was also reported by Bonadonna (1939) who concluded that
semen of cattle can be stored from 50 to 120 hours.
Phillips (1939) using egg-yolk phosphate diluter reported conception
with 100-hour-old semen.

Successful conception was also reported by

Phillips and Lardy (19U0) by using egg-yolk phosphate buffered bull semen
stored for 130 to 180 hours.

Herman et al. (19U3) obtained successful

results with semen having 10-90% motility before shipment and which was in
transit from U 8 to 130 hours.
conceived.

Out of 12 cows that were inseminated, 8

Vaidya. and Bhattacharya. (19U5) reported conception in cows

with semen stored for 6 d a y s .

23

Attempts have been ma.de by some of the research workers to determine
the effect of length of semen-storage on the rate of conception or per­
cent of non-returns.

Herman and Ragsdale (1939) found that approximately

one-third more services were required per conception with I4. to 5-hour-old
dairy bull semen as compared with semen less than 1/2 to 2-hour-old.
Henderson (1939) using SGC-2 as diluter (Milovanov formula) observed
no decrease in rate of conception (apparent pregnancy) with diluted semen
stored up to 30 hours.
Burch (1939) reported that the use of good samples of stored semen
for insemination of cows, 2k or more hours after collection, resulted in a.
conception rate which compared favorably with that obtained by the use of
average fresh semen samples.
Margolin et al. (19U3) observed a slight decrease in the percentage
of conception (conception was ascertained by palpation or b y calving)
with the use of 1-dav-old semen (6 1 .9$) as compared to that obtained with
fresh semen (6 3 .7$).
Lasley and Bogart (19U3) in a. study on range cattle failed to store
non-diluted semen successfully.

However, with the use of egg-yolk-buffer,

they were able to maintain a. satisfactory level of fertility of diluted,
semen stored for 2 days .

These investigators obtained 60% conception rate

for non-stored semen and 5 7 .1$ conception rate for diluted semen stored
for 2h hours and for it8 hours .
Underbjerg et al. (19U2) in a study involving 931 cows reported that
regardless of the kind of diluter used, the conception percentage (con­
ception ascertained by palpation or by calving) obtained with the use of

2h

semen stored from 2I4-I77 liours was much less than that with the use of
fresh semen samples (l-hour-old).

The difference in conception rate be­

tween the stored and fresh semen samples was found to be highly significant.
Schultze et al. (19U8) in a study with 25.1U6 first and second
services frorn over 2,300 semen samples used in 13 artificial breeding
locals at Nebraska, found. that the percent of non-returns decreased an
average of U .61 percent per day up to U days of storage of semen.

The

average decline in percent of non-returns from the 1st day to the 2nd
day of storage of semen; from the 2nd to 3^d day; from 3^d to J.itli day were
3.32, U.63 and b.$h percent, respectively. The percent of non-returns for
the 2-year period of study for 1, 2 , 3

a-nd U-day-old semen was found to

be 63.21, 37.69, 33-26 and Uo.72 percent, respectively.

The Chi-square

test showed a highly significant difference in the non-return rates re­
sulting from the use of 1 to Jj-day-old semen.
Decrease in conception rate with increase in the age of semen was
also noted by Schaefer (19U8) in a study of breeding records of NEPA
Artificial Breeding Co-op, Tunkhannock, Pennsylvania.

Schaefer reported

that with the use of fresh, 1-da.y, 2-day, and 3-day-old sernen, the percent
non-returns obtained was . 7 0 , 6 6 , 6l and 36 %, respectively.
Erb et a l . (1930) in a study involving 23,936 first and second
services from bulls at Northwest Co-op Breeders

(h it.

Vernon, Washington)

and Evergreen Breeders (Chehalis, Washington) found that the average o?
percent of non—returns with 1—day—old. semen was equal to that of 2 —day—old
semen (6U$) .

However., a decrease in non-return rate was noted with 3-day-

old semen (39$).
returns t o ■be 63$.

These investigators reported an over-all percent of non­

Swanson (1931) analyzed the records of the East Tennessee Artificial
Breeders1 Association, Inc. during two management periods.

In the first

period when semen was collected in the early morning and no bactericidal
substances added to semen, he obtained non-return rales of o3.3, 62 and
55 .7$ with 1-day-old (5 to 13-hour-old), 2 day-old (29 to 37-hour-old) ,
and 3-day-old (33 ho 6l-hour-old) semen, respectively.

Statistically,

the difference in non-return rate between 1-day and 2-aa.y-olu semen was
not significant.

However, a highly significant difference was noted in

non-return rate between 2-day and 3-day-old semen.

During the second

period of management, semen was collected in late afternoons and penicillin
and streptomycin were added to the semen.

The non-return rates obtained

during this period, with 1-day-old (16 to 2 6-hour-old) semen and with
2-day-old. (1|2 to 30-hour-old) semen, were 61.3 and 36.2 percent, respectively.
Statistically, the difference in non-return rate between 1 and 2-day-old
semen was found to be highly significant.
Sweetman (1933) under Alaska conditions reported that the percentages
of non-returns on 1st and 2nd services for 1 to li-day-old semen were 38.7,

33.3, U8.1 and U3.3$, respectively.
Controversial results have been reported b y various investigators
regarding the effect of storage of semen on the conception r a t e . Willett
et al. (i960) after a. study involving more than 1,300 inseminations came
to the conclusion that with proper precautions in handling the semen and
diluent, the percent of non-returns resulting from diluted semen stored
up to b days is as satisfactory as that obtained with semen used on the
day of semen collection.

Further investigations confirmed the same general

26

conclusion (Salisbury 19Ul) .

Similar results ha.ve also been reported by

various investigators . Henderson (l9Uo) stated that with good quality
semen that is properly cooled and diluted, no significant decrease in
fertilising capacity should result up to U days of storage.

Anderson (19U5)

reported that conception rate from the use of semen stored up to 72 hours
was equal to that of fresh semen.
The literature reviewed above shows minor disagreement in the results
obtained with the use of stored semen.

The controversial results reported

may be due to one or more factors affecting conception rate or percent of
non-returns.

Variation in potential fertility of semen, or variation in

method of handling of semen might be responsible for the disagreement.
Various factors have been reported to affect conception rate.

Some of the

important factors are:

(b ) Relative Fertility of Bull
Bulls vary in fertility.

White et al. (1925) in a. study on UO bulls

noted a great variation in the fertility of b u l l s .
required for conception varied, from 1 to 3 .16.

The number of services

A still larger variation

was reported by Miller and Graves (1932) who observed that the number of
services for a conception from the bulls varied from 1 to 5.65.

Schultze

et al. (191*8) in an investigation to determine the effect of 1 to b-dayold semen on percent of non-returns, found that bulls varied in the rate
of decline of conception rate.

However, a daily decline in fertility of

semen from a group of bulls having more than 60% of non-returns did not
differ significantly from that of semen obtained from group of bulls having
less than 55?o of non-returns.

Swanson (1951) al so noted a. great variation

27

in the decline of breeding efficiency between bulls with age of semen.
However 3 no significant difference in the decline of breeding efficiency
with age of semen wa.s found between the group of bulls having low breed­
ing efficiency and the

group of bulls having high, breeding efficiency.

(c) Relative Fertility

of Cow and Cow

Families

According to Herman and Ragsdale (19U6) cows are more
for lowered conception

rate rather than the impotency

to be blamed,

of the b u l l .

Erb

et al. (19U0) and Trimberger et al. (19U5) noted a variation in the fer­
tility (breeding efficiency) between cow families .

Seath et_ al. (19U3)

reported a. large variation in the breeding efficiency between cow families,
ranging from a low of 1|0.6% to a. high of 92.3% conception rate.

These

investigators, therefore, believed that breeding efficiency may be inr
herited.

(d) Breed of Animal
Schultae et al. (19U8) found that the over-all percent of non-returns
for Holstein, Guernsey and Jersey were 57.66, 56.lU and 5° .72 percent,
respectively.

Lewis (l9hSb) reported that the percent of non-returns for

the Holstein breed was 6.3% greater than that for the Guernsey breed.
On the contrary, Erb et al. (1950) found no difference in percent of non­
returns for Holstein (61;%) and Guernsey (61;%) .

However, the Jersey was

found to have the lowest percent of non-returns (59%) .
Mercier and Salisbury (19U6) reported that the conception rate based on
two months1 non-returns wa.s greater by 12.2 percent in the Holstein breed
than the Guernsey Dreed.

In an attempt to attribute this breed difference

28

to semen quality, these investigators found no statistically significant
difference between breeds in semen volume, percent motile sperm and con­
centration.

However, the breed difference in percentage of morphologically

abnormal spermatozoa was highly significant.

Contrary results were ob­

tained in a later study by Mercier and Salisbury (19U7) who observed that
the Guernsey bulls had a. slightly higher fertility (percent of non-returns)
than the Holstein-Friesian b u l l s .

(e) Health of Animal
White et al.
and reported that

(192.5) studied the influence

of B. abortus infection

1.82 services were required per conception in the case

of non-reactors whereas 2 .09 services per conception were, required in the
case of the reactor cows.

Fitch et al. (1929) reported 1.7 services per

conception for a clean herd as against 2 .U services per conception in the
herd infected with Bang's disease.

According to Perry et al. (195)2)

severe abscesses and swelling, trauma, (inflamed scrotum) , epididymitis and
hypoplasia adversely affect the breeding powers in b u l l s .

(f) Age of Animal
Gowen and Dove (1931) in a. study involving 7,679 cows observed some
decline in conception rate as age of the cows advanced.

Conception rate

was found to be 70% for the females under one year of age whereas it was

7% for cows of 17 years of age . A decline in

the fertility of the bulls

as age of bull advanced was also noted.
Miller et al. (1932) found that more services were required per con­
ception to the heifers than to the cows.

These investigators also noted

29

that more services were required by females for conception with mature
bulls (above 6 years of age) than with young bulls (under 6 years of a.ge) .
With mature bul l s , 3.83 services were required whereas with young bulls,
2.28 services were required per conception.
Morgan and Davis (1938) reported that virgin heifers required more
services per conception than cows from 2 to 9 (inclusive) years of age .
However, little difference was observed in number of services required
per conception in cows of ages from 2 to 12 (inclusive) years with the ex­
ception of 10-year old c o w s . They also reported that the conception rate
was the highest with young bulls under 2 years of age.

However, a very

little difference was noted in the number of services per conception with
bulls from 2 to 6 (inclusive) years of age.

Further, in an analysis of the

data, on the mating of bulls and cows of varying ages these investigators
concluded that the number of services required per conception was the
smallest when 2-year-old bulls were mated with 2-year-old cows.
Bartlett and Perry (1939) reported that heifers required more services
per conception than cows.

They observed that a higher conception rate

was generally obtained with young bulls.

1 tendency for young bulls

settling the heifers at a higher rate than mature bulls was also noted.
Bowling, Putnam and Ross (19U0) reported that heifers required a
significantly greater number of services for conception than cow s .

They

also found that less services per conception were needed by heifers when
bred to bulls tinder U years of age as compared to older bulls . A gradual
decline in the breeding efficiency of bulls with increasing age was also
not e d .

30

According to Erb, Wilbur and Hilton (I9l|0) breeding efficiency was
highest in 1 and 2-yea.r-old bulls.

Thereafter, a gradual decline in

breeding efficiency with advancing age resulted.
Hilder et al. (19UU) in a study on the Bureau of Dairy Industry herd
at Beltsville, Md., observed that the number of services per conception
was higher for heifers than for c o w s .

These investigators also noted a

gradual decline in the breeding efficiency of bulls with increasing age.
However, the 7-year-old group was found to be an exception to this
observation.
Tana.be and Salisbury (19I46) studied the effect of a.ge (1-12 years)
of bull on conception rate and found that young bulls of the age group
1-3 years had the highest breeding efficiency.

(g) Month and Season of Breeding
Miller and Graves (1932) in a study of breeding records of 22 Holstein
and Jersey bulls at Beltsville, M d ., found that on an average the breeding
efficiency (based on conception regardless of whether females reproduced
normal live-calves) was lowest in July, August, September.

This lowered

breeding efficiency in summer months was attributed to high environmental
temperature.
Morgan and Davis (1938) in a study of records of 5 dairy breeds at
the University of Nebraska, reported that the percent of conceptions x^as
the lowest in August (35.9%) and September (35.lh%) but it was highest
in December (51.61%).
of conceptions in July.

These investigators also noted a higher percent

31

Erb et a l . (I9I4O) in an examination of the records of the Purdue
University dairy herd for a 20-year period found that breeding efficiency
based on calving results was highest in M a y (7h.3%) and lowest in August

.2 %).
Seath and Staples (I9I1I) in an analysis of the records of the Worth
Louisiana experimental (Bangs free) herd and the Louisiana State University
herd located in South Louisiana, reported that maximum number of services
per conception were required during summer m o n t h s .

In the experimental

herd, conception rate was highest during winter and second, highest in fall,
whereas, in the University herd, conception rate was highest in the fall
and second highest conception rate was noted in winter season.

Later,

Seath, Staples and Neasham (19U3) in a. study of breeding records of the
Louisiana State University dairy herd and the North Louisiana Experiment
Station herd", reported that conception rate was the highest in fall and
winter and. lowest in spring and summer season.
Phillips et_ al.(l9i-k3) in an analysis of 1,139 matings from Beef
Shorthorn and Milking Shorthorn bulls found that the breeding efficiency
expressed as the percentage of fertile matings, was the highest in April
(59.6^)

and the lowest in August (I4O.8/&) .

The breeding efficiency in

summer season (July-September) was found to be the lowest of all seasons.
According to Hilder et al. (19UU) the number of services per con­
ception was much higher in July and August than other months of the year.
It was also higher during September, February and M a r c h .

During the fall

season however, a sharp decline in the number of services per conception
was observed.

The lowest conception rate obtained during midsummer was

attributed in part to high environmental temperatures.

32

Trimberger and Davis (19^5) in an analysis of the breeding records
for the Ayrshire, Guernsey, Jersey and the Holstein females of the
University of Nebraska dairy herd found that of all the seasons, the con­
ception rate a.s determined b y actual pregnancy examinations per rectum
was the lowest in summer. The number of inseminations required per con­
ception was the highest in August and was higlily significant.
Ellenberger et_ al. (l9Ub) found little or no relationship of season
of the year with conception rate under Vermont conditions.
Mercier and Salisbury (19U6) reported a. highly significant monthly
variation in the fertility (percent of non-returns) of bulls of N e w York
Artificial Breeders’ Co-op, Inc.
Mercier and Salisbury (l9U7a) in a study of conception rate of cattle
under natural breeding conditions in Eastern Canada found that the con­
ception rate expressed as percent of successful services was the lowest
during winter and spring and highest during summer and fall.
ences in the conception rate between seasons were significant.
investigators concluded that light (length of day light)

The differ­
These

is an important

factor in the breeding efficiency of cattle.
Mercier and Salisbury (19U7b) in an analysis of the artificial breeding
records of about 12^,000 cows and 71 bulls in N e w York State reported that
the breeding efficiency expressed as percent of non-returns was the lowest
in winter.

A significant correlation between the breeding efficiency and

the length of daylight was also reported.

Effect of season on the breeding

efficiency was more readily noticed In the younger (under h years of age) and
older (over 8 years of age) cattle than in the mature cattle (1+ to 8-year-old) .

33

Schultze et al. (19I1.8) of Nebraska State reported that the over-all
conception rate expressed as percent of non-returns was the highest in
June and was the lowest in August.

Spring season was found to be the

best for conception rate and summer season the poorest.

The percent of

non-returns for spring, winter, fall and summer seasons was found to be
59.36, 57.63, 56.90 and 52 .U8, respectively.

In an analysis of the same

data by age of semen (l to U days), these investigators obtained no
seasonal difference in the rate of decline of percent of non-returns.
Lewis (l$?l|8b) in a study of breeding records of Holstein and Guernsey
bulls of Michigan Artificial Breeders * Association reported that the per­
centages of non-returns with these bulls were poorer in winter and summer .
The percent of non-returns for Holstein breed was found to be highest in
March and April (spring) whereas for Guernsey bulls, breeding efficiency
was highest in October and November (fall season).
Erb et al. (1952) in an analysis of breeding records of Guernsey,
Jersey and Holstein bulls used b y Northwest Co-op Breeders, M t . Vernon,
Washington, reported that the average non-return rate was the lowest in
January and highest in September.

Breeding efficiency showed a. definite

pattern in that the percent of non-returns was lowest in January to April,
followed by a gradual increase to the highest level in September, October
and November.
Sweetman (1953) using dairy bull semen up to 80-hour-old under Alaska
conditions, noted that the percent of non-returns on all 1st and 2nd
services was the liighest in fall (59.1^) , whereas, it was the lowest in

3h

winter ( b 9 .2%).

The percent of non-returns for summer was $b.2% whereas

it was 5 2 .9% for spring.

(h) Time of Insemination in Relation to Time of Ovulation
Kufarev (1935) reported that the second half of estrus was the opti­
mum time for insemination.
According to Kirillov (1937), in 60% of the cows that were bred at
the beginning of heat, re-breeding was necessary whereas in only 26% of
the cows of the sarne herd tha.t were bred 18-2U hours after the beginning
of heat, re-breeding was required.
Herman (1939) inseminated cows h to 12, 12 to 2 h , 2)4. to I48 and I48 to
60 hours following the first signs of heat and noted that the average
number of inseminations required per conception was
2.70, respectively.

1.72, 2.19, 2.13 and

Thus, a high breeding efficiency was observed when

cows were bred during "active heat".

Herman, therefore, concluded that

for good results cows should be -inseminated within 12 hours after the first
signs of h e a t .
Bartlett and Perry (1939) obtained highest rate of conception when
inseminations were done during full and la.te estrus .• The periods of 8-12
hours and of 12 -2U hours from the time of onset of heat were considered
by these investigators as full and late estrus, respectively.
Trimberger and Davis

(19U3) in a. study involving 295 dairy cows and

heifers found that when females were inseminated at the middle of estrus
or when bred artificially at the middle of estrus and rebred in 2h h o u r s ,
the conception rate was much higher than when inseminated at the start of
estrus or at 12 hours or more after the end of estrus.

35

Barrett and Caside. (19U6) observed a. little difference in the pe r ­
centage of conception when cows were inseminated from 3 to 25 hours from
the onset of heat.

On the contrary, when cows were inseminated less

than 3 hours or when inseminated 25 or more hours after the onset of
heat, lower conception rate resulted.
Trimberger (195-8) found that when females were inseminated more than
6 hours but less than 25- hours before ovulation,
ception were obtained.

v ery

high rates of con­

But when the females were bred after ovulation,

very low conception rates resulted.
Brewster et al. (195-0) fotind that the average time of ovulation from
the end of the estrus was 13.57 ± 0.63 hours.
average 3.0U hours earlier than cows,

Heifers ovulated on an

bo significant difference between

the age of animal and the rate of sperm travel was noted.

The minimum

time required for sperm to reach the fallopian tube in mature cows was 5
hours and 30 minutes as compared to 5- hours and 15 minutes in heifers .
VahDemark et al. (1951) using a. more refined technique found that
the motile spermatozoa was transported from cervix to ovarian portion of
oviduct in 2.5 minutes after insemination.

(i) Time of Breeding after Calving
In a. study of 79 cows having fairly good breeding efficiency, Hofstad
(1951) reported that when the cows were bred oefore the 60th day following
parturition, the 'oercentage of abortions, cases of metritis, aystocias
and retained placentae were relatively high and conception rates were rela­
tively low as compared with the cows bred after the oOth day of calving.

36

The results suggest that the breeding of the cow before the 60th day
after calving should be discouraged.
VanDemark and Salisbury (1950) in a study involving 1,67U pregnancies
(pregnancies confirmed b y calving) found that on an average, when cows
were first bred 1-20, 21-lj.O, l|l-60 and 61-80 days after calving, the p e r ­
centages of services resulting in conceptions (reproductive efficiency)
were 35.0, J4I.0 , U5.0 and 50^.8 respectively.

W i t h a further increase

in post-partum interval to 1st service, the average reproductive efficiency
increased and reached the maximum (57.8/0 ■when the cows were first bred
101-120 days after calving.

Thereafter, the reproductive efficiency showed

a decline and reached the level of h6.3% when the post-partum interval to
first service was 201 or more days.

C j) Skill and Experience of Teclmicians and Inseminators
Per r y and Bartlett (19U5) have pointed out that the skill of the tech­
nician is an important factor in relation to conception rate .

Dickensheet

and H e r m a n (19U9) have quoted Peterson who reported that experience of
the inseminators does ha.ve a. great influence on the conception rate .
According to Peterson, efficiency of the inseminators wa s found to reach
the pe a k with an experience of 7 m o n t h s .

(k) Herd Management
Herd management has been shown to affect conception rate .

In the

efficient herds, poor management has been reported to have required 1.90
services as compared to 1.7U services per conception in the satisfactorily
managed herds (Dickensheet et al. 1 9 U 9 ) .

37

(l) Breeding Efficiency b y Artificial vs. Natural Method
For the success of artificial breeding program the breeding effic­
iency obtained with artificial insemination must compare favorably with
that by natural s e r v i c e .
The number of artificial services per conception reported b y various
investigators varies from about l.o to 2.07.

According to Davis and

Trimberger (1937), Swanson and Herman (l9hlb) two services by artificial
breeding were required per conception.

Cole and Winters (1939) reported

that 1.77 artificial services were required per conception.
(1939) required 1.91 inseminations per conception.

Henderson

Trimberger et a l .

(I9li5) reported, that 1.95 inseminations per conception were required.
These investigators also reported that 60.25% of the females conceived
to the 1st s e rvices, 18.31 percent to the 2nd, 7.82 percent to the 3rd
service, 1+.23 percent to the Uth, 3.91 percent conceived with 5 or more
services and 5.U8 percent of the females were found to be sterile.

Tanabe

and Salisbury (19U6) in a study of the records of the N e w York Artificial
B r e e d e r s 1 Cooperative Association found that on the average 2.07 services
were required per conception b y artificial insemination.

Schaefer (19U8)

in a. study of breeding records of 23,lUl cows reported that 1.53 services
b y artificial breeding were required per conception.
The number of natural services per conception reported b y various
investigators varies from about 1.5 to 2.2.

Morgan and Davis (193&) found

that on an average, females of all ages required 2.21 natural services per
conception.

In a. study of 20 year period breeding data of Missouri

Station herd, Herman (1939) reported that on the average 1.53 natural

38

services were required per conception.

Later, in a study of breeding

data of 2 year period, Herman found that 1.66 services were required per
conception when half the herd was bred naturally.

The other half herd

which was bred artificially required 1.59 services per conception.
Dokudovskii (193^) found a little variation in conception rate between
the natural and artificial breeding.

Erb et al. (19^0) in a study of

breeding records of Purdue University Dairy herd reported that 1.56
natural services were required per conception.

Perry

and Bartlett

quoted Larsen (Veterinarian in Denmark) who reported that

the rate

(19l5)
of

conception b y artificial breeding (1.68) was as good as by natural breeding.
From the literature cited above, it can be said that the artificial
breeding is as efficient a.s the natural breeding from the standpoint of
breeding efficiency.

(B)

EXPERBiENTAL PROCEDURE

The ’’Final" summary cards were used to arrange and tabulate the breed­
ing data in order to study the influence of various factors on percent of
non-returns (percent N.R.) as per outline mentioned below.

The factors

studied were age of semen, bull, breed, month and season of year, registered
and non-registered females .
(l) Yearly percent of non-returns for total current services (l, 2,
3, U, 5 and over) t o all females, by bull and by: (a)
3, k, 5 day-old), (b) irrespective of age of semen

age of semen

(l,2,

39

(2) Y e a r l y percent of non-returns for total current services (1, 2,
3, b, 5 and over to all females, by breed and by:

(a) age of semen (1,

2, 3, ^4, 5 day-old), (b) irrespective of age of semen
(3)

Yearly percent of total current services (1, 2, 3, U, 3

and over)

for ea.ch a.ge of semen, b y breed
(1|) Y e a r l y percent of non-returns for total current services (l, 2,
3, b, 5 and over) to all dairy females regardless of breed, by:
of semen

Cl, 2, 3, U, 5 day-old), (b) irrespective of age of semen

(5) Percent

of non-returns for total

current services (l, 2, 3, U,

5 and over) to all females, b y breed, b y month of
(a)

(a) age

breeding and by:

age of semen (1, 2, 3, b, 5-day - o l d ) , (b) irrespective
(o) Percent

of non-returns for total

of age of

current services (1,

semen

2, 3, U,

5 and over) to all females, b y breed, b y season of breeding and by:
(a.) age of semen (1, 2, 3, U, 5-day old), (b) irrespective of age of semen
In the present investigation, the months were grouped into seasons
as follows:
Fall season:

September, October and

November

W i n t e r season:

December, January and February

Spring season:

March, April and M a y

Sutnmer season:

June, July and August

(7) Y e a r l y percent of non-returns with 1-dsy-old semen for 1st serv­
ice registered females and for 1st service non—registered females

Dy

bull

(Holstein)
(8) M e a n and the distribution (standard deviation)

of total current

services (l, 2, 3, b, 5 and over), b y breed, for each da.te of semen col­
lect ion for a bull.

hO

The results obtained in the present investigation were tested for
level of probability and at the 1% level of prob­

significance at the
ability.

In this manuscript, the %% level of probability will be referred

as 5% level ana 1% level of probability will be referred as 1% level.

(C)

KSSULTS

Table I shows the yearly percent of non-returns on total current
services (l, 2, 3,

U, 5

and over) by bull, and by:

(b) irrespective of age of semen.

(a) age of semen,

From the Table, it can be seen that

the yearly percent of non-returns for both dairy and beef bulls decreased
as the age of semen advanced from 1 to 5 days.
were noted.

For example, in bull 123 (code number), the percent of non­

returns for 5-bay old semen wa.s 1% greater
semen.

F ew exceptions, however,

(U9-U8)

than that for li-day-old

This is more likely to be due to less number of total services

with 5-da.y-old semen.
Bulls were found to vary widely in the amount of decline of semen
fertility (.percent of non-returns) for day-to-day storage of semen.

In

bull 126, the percent of non-returns declined 1% (71-70) from 1-dsy to
2-day-old semen,

from 2-day to 3-da.y-old semen, 131% from 3~da.y to

U-day-old semen and 1% from U-day to 5-day-old semen.

On the contrary,

in bull 128, the percent of non-returns declined 10% from 1-da.y to 2-dayold semen, 10 % from 2-day to 3-day-old. semen, 1% from 3-day to Jb-day-old
semen and 3% from U-day to 5-day-old semen.

A wide variation was also

noted between bulls in the average daily decline of fertility of semen

TABLE I
YEARLY PERCENT OF NON-RETURNS BY BULL AND B Y A G S OF SEMEN

Age of Semen in Days
2

1

1+

3

Total

5

Bulls

106
107
111
113
US
116
117
121
122
123
125
126
127
128
130
131
135
136
12+0
ll+ l
li+ 3
11+1+
il+ 5
lli 6
111 7
H e
11+9
150
151
152
155
156
157
15&
159
160
161
162
163
161
165
166
lo 7
168
169
170
1+05+
J . T r\

Services
Number

N.R."
%

61+6
1+51+

70
70

hi 3

13

581+
1*063
1+68
1+30
1*550
799
1+99
1+60
755
559
1 ,1 2 0
651
i+19
580
1*217
362
53U
1*701
1*808
526
126
7 69
531+

12

13

12

197
1+5
20
265

71
71
66
71+
71
71
62
69
75
61
71
71+
71+
71
69
69
71+
75
68
73
67
69
77
71+
66
72
72
62
78
71+
69
66
72
72
73
■70
70
70
67
85
50

ono

AA

h6
371
5H+
1 ,3 2 9
209
61+1+
1 ,2 3 3
1 ,2 5 8
99
1+1+0
8 57
1+88
1*21+2
61+7
182
3 1+0

13k

Services
Number
690
683
959
556
1*51+0
608
673
2 ,3 1 3
1 ,1 3 8
91+9
1*051
1,1+68
1*183
1 ,6 8 1
i,5 i+ o
1+22
650
1 ,9 0 9
505
912
2*1+56
2 *556
966
211
1 ,2 0 1
1 ,0 5 5
95
905
1,031+
1 .9 9 7
335
95U
2 ,5 0 5
1 ,8 6 6
135
758
1*1+32
931+
1 ,9 6 3
1 ,3 3 1
1+53
691
305
271
91
38
1+57

H.R.
%
69
61+
71
61+
62
61+
65
71
56
68
65
70
58
59
76
50
60
68
71
63
56
56
73
61
61+
63
62
57
69
65
•60
71
68
52
70
65
63
56
68
68
72
62
66
60
56
66
35
At

Services
Number
235
81+6
392
11+5
731+
383
1+55
1*576
91+9
1*111+
71+0
1*361+
627
1 ,1 5 9
2 ,0 6 0
153
257
1*897
297
561
1 ,0 3 5
2*139
635
71+
577
675
78
591+
1 ,0 1 8
1,1+1+1+
136
558
1 ,2 3 9
9 36
72
1+51+
1 ,6 9 1
666
1*01?
587
227
31+3
153
1 5 I+
23
22
221
T A)i

N.R.
%

Services
Number

N.R.
%

57
50
60
58

30
291
62
16
99
92
139
667
391+
650
175

1+3
52
63
53
1+9
51
50
62
37
1+6
1+3
51+
l+l
1+2
69

hi
61
51
67

hi
59
58
65
1+7
1+9
72
1+0
1+9
59
56
51+
1+5
51
70
55
51+
52
28
1+9
65
58
61
66
60
1+1+
72

&

56
1+3
59
61
61+
53
55
1+7
1+8
61+
33
A?

126

119
351+
1*237
27
51
629
125
157
125
610
199
16
72
11+1+
12
205
1+83
510
25
107
222
158
10
76
772
172
131
101
20

hh
23
1+3
O

5
1x2
1 65

Services
Number

1+3
52
62
51+
36
1+2
66
31
57
1+0
25
37
59
1+7
1+0
61+
59
l+l
70
53
50
31
53
52
60
52
39
53
67
1+0

8
30
17
7
22
19
22
80
57
70
52
125
33
59
11+3
1+
29
71
12
1+2
37
193
90
2
18
25
2
33
35
100
11
21
1+5
1+7
8
22
97
26
51+
21
18
6
5
3
7
2

38
In

10

hh

6

N.R.
%
50
1+3
65
29
55
56
55
66
1+0
1+9 ■
1+6
53
1+5
39
60
0
1+1
51
75
55
1+3
1+1+
56
50
61
68
0
56
71
59
36
52
62
1+5
50
50
39
29
57
67
50
17
1+0
33
57
100
38
1+7

Services.
Number

N .R.
%

1 ,6 0 9
2,501+
1 ,9 0 3
1*309
3 .1+58
1*570
1,91+9
6 ,1 8 8
3*337
3 .2 8 2
2,1+78
l+*l+58
2 ,5 2 1
l+ ,3 7 3
5 ,8 3 1
1 ,0 2 5
1 ,5 6 7
5 ,9 2 3
1 ,3 0 1
2 ,2 2 6
5 ,351+
7 ,5 0 6
2,1+36
1+29
2 .6 3 7
2,1+33
233
2 .1 0 8
3 -081+
5*380
716
2,281+
5*21+1+ ■
l+ ,3 3 9
321+
1*758
1+ ,01+9
2 ,2 8 6
U*U07
2 ,0 8 7
900
1,1+21+
620
666
172
87
993
1.1+19

67
61
69
06
62
65
62
69
53
62
62
66
55
57
72
53
61
61+
68
62
58
57
71
63
63
61
1+9
55
67
63
61
69
67
53
7 2'
66
59
52
66
67
69
61
67
59
59
69
39
56

ii-LU
612
616
k n

6i t
621
622
623
h2h
625
1x2 6
629
1x30
631
632

h33
Lx3U
135
636
1x37
636
539

hiiO
661
662
663
666
665
666
66 7
668
66 9
601
602
6 03
605
606
cOC
60?
612
615
61b
616
6 19
620

621
7 92
793
795

'

572
62
367
2 06
165
363
517
277
562
260
182
596
505
391
52
3 57
527
122
252
2 60
156
102
313
213
21c
53
33 9
130
62
65
85
17
23
351
27 2
7
33
223
136
195
313
318
175
198
32

1]

110

17 s

795

66

796
7 97
796
799

29
159
155
156
52
33
11
35
67

601
605

606
608
809
610
812
■-H
t6feL _
1* won-

00
61
71
75
66
63
71
68
57
66
67
59
62
67
06
71
79
72
67
63
73
56
75
69
7!
Ob

c2
6?
70
75
63
77
63
75
o3
70
71
79
75
6c
=5
62
63
6=
70
72
cO
75
75
60
52
77
72
68
75
55 .
73
75
62

pp 1
1 ,0 0 2
121
905
355
291
639
1 ,0 8 1
665
951
766
291
981
863
687
65
6 65
1 .1 2 9
256
555
530
361
160
556
516
565
10?
695
301
151
122
193
27
33
553
5o2
17
50
36 ?
157
303
568
515
356
520
35
116
363
515
371
5c
552
3*7
367
515
256
156
33S

53-I_

55
67
65
57
56
61
61
52
65
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53
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70
71
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57
68
57
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65
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57
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56
63
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75
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o9
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59
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61
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756
79
721
176
126
199
727
587
865
533
159
655
653
5cO
28
530
628
166
306
169
251
108
379
351
366
79
655
233
97
102
169
19
20
265
355
13
f'
270
71
166
565
358
265
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92
336
535
306
66
678
295
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372
79
388
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278
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20
173
63
56
225
52
55
126
35
23
66
66
10
69
26
161
363
50
61
196
57
51
103
17
88
56
?6
•; 5 0 0 J ie a f la n e ; yoO A n g

51
50
63
38
3c
56
61
61
67
60
100
60
56
66
100
50
66
100
65
27
62
50
56
55
5?
50
69
67
33
33
100
50
100
53
6 fc
-

0
60
0
50
50
50
50
50

0
71
52
63
60
66
66
65
63
66
65

60
56
37
51

29

66

2 ,6 3 8
281
2 ,3 7 6
'6 3 6
612
1 ,2 6 7
2 ,6 2 2
1 ,7 3 6
2 ,9 3 0
1 ,6 3 0
669
2 ,3 7 5
2 ,1 5 6
1 ,7 0 7
138
1 ,6 9 0
2 ,6 0 6
556
1 ,2 3 1
892
910
396
1 ,3 6 9
1 ,2 2 2
1 ,2 3 9
257
2 ,1 0 5
786
366
298
565
68
7c

1 ,1 6 6

1 ,1 8 1
60
97
973
377
756
1 ,5 6 0
1 ,2 6 2
915
1 ,6 0 7
89
267
1 ,0 5 6
1 ,5 2 5
900
163
1 ,5 2 3
958
1 ,0 5 6
1 ,1 5 3
77 6
376
367
1 ,6 6 3
1 ,0 6 5

575
656

52
59
66
52
58
63
61
50
63
57
53
60
60
53
60
65
69
61
52
70
65
66
5°
66
62
58
59
68
66
59
71
65
55
57
62
66
69
69
59
ol
53
62
60
62
57
73
65
68
67
50
70
70
53
58

65

56

65
55
66
50

60

(percent of non-returns). For example, the average daily decline of
semen fertility for bull 126 was h .5% (71-53), whereas, it was 7.5$ for

n

bull 161.
Bulls varied widely in the ability of semen to maintain fertility
(percent of non-returns) during storage for 5 days.

In bull 130, the

yearly percent of non-returns for 1-day-old semen was 75$,whereas it was
60$ for 5-day-old semen.

Thus, there was a drop of 15 percent of non­

returns from 1-day to 5-da.y-oId semen.

On the other hand, in bull 161,

the yearly percent of non-returns for 1-day-old semen was 69$,whereas, it
was 39$ for 5-day-old semen,resulting in a drop of 30 percent of non­
returns from 1-day to 5-bay-old semen.
There was a great variation in over-all (i.e. regardless of age of
semen) yearly percent of non-returns between bulls in a. breed and between
bulls irrespective of breed.

In Holstein breed, for example, the over-all

percent of non-returns for bull 162 was 52$,whereas,it was 72% for bull
130.

The over-all percent of non-returns for Holstein bull lli5 was 71$,

whereas,it was only 39$ for the Guernsey bull U 0 5 .
Table II shows the yearly percent of non-returns for total current
services (1, 2, 3, U, 5 3rd over) by breed and by age of semen in days.
In Figure 1 is presented, by breed, the effect of age of semen on yearly
percent of non-returns based on total current services (l, 2, 3, b, 5 and
over). From the Table II and Figure 1, it is clear that the yearly per­
cent of non-returns in Holstein, Jersey, Red Dane and Angus breed, declined
for day-to-day- storage of semen.

The same was true in Guernsey breed ex­

cept tha.t the percent of non-returns with 5-day-old semen was slightly

TABLE II
YEARLY PERCENT OF NON-RETURNS BY BREED AND B Y AGE OF S M E N

Age of Semen in Days
1

2

6

3

5

Breed
Lumber
Services

%
N.R.

Number
Services

)'o
N .R.

Number
Services

%
N .R.

Number
Services

rl
7°

i'i,R ,

<-L

Number
Services

N .R.

Holstein

29,790

70.52

68,632

66.12

32,595

57.13

10,730

51.96

1,632

51.31

Guernsey

3,61a

67.02

17 .226

60.57

11,695

56.06

6,366

50.00

765

51.36

Jersey

2,286

66.51

3,663

61.69

2,761

56.36

887

53.33

133

67.37

Red Dane

265

76.76

2,526

61.69

2,756

56.21

1,290

52.09

236

67.66

Angus

936

72.01

2,708

69.76

2,296

62.62

1,167

59.13

253

56.92

Er
W

111
------

Holstein

______

Guernsey

■■■ Jersey
.....

Red Dene '

■#---#—

Angus

80

Percent

of Hon-Returns

70

60

50

Ho

2

1

3

h

Age of Semen in Days
Fig. 1.

The effect of age of semen on yearly percent of
non-returns, by breed.

5

55

higher (51.3^-50.00 = 1.35$) than that -with 5-day-old semen.

This dif­

ference of 1.35 percent, however, was not statistically significant
(5/i level) .
In Holstein and Guernsey breeds, highly significant differences
(1$ level) were noted in the yearly percent of non-returns between 1 and
2-day, 2 and 3-day, and between 3 and 5-day-old semen, but not between
5 end 5-da.y-old semen.

The difference in percent of non-returns between

U and 5“day-old semen was not statistically significant (5/6 level) .

In

Jersey and Red Dane breeds, highly significant differences (1$ level) were
noted in the yearly percent of non-returns between 1 and 2-day and between
2 and 3-day-old semen, but not between 3 and 5-day and between 5 and 5-dayold semen.

The difference in percent of non-returns between 3 and 5-da.y

and between 5 and 5-day-old semen was not statistically significant
(5/o level) . In Angus breed, there was a highly significant difference
(1$ level) in yearly percent of non-returns between 2 and 3-day-old semen
but not between 1 and 2-day, 3 and 5-day, and between 5 and. 5-da.y-old
semen.

The percent of non-returns between 1 and 2-day, 3 and 5-day and

between 5 and 5-day-old semen was not stallstically significant (5$ level).
From Table II it can be stated that there was a. wide variation be­
tween breeds in the average daily decline of semen fertility (percent of
non-returns) during storage of semen.

The average daily decline of semen

fertility up to 5 days of storage of semen was the highest (75.75-57.55=6.83$)
5
in Red Dane, whereas, it was the lowest (3.77$) in Angus breed. In other
words, the ability of semen to maintain fertility during the storage period
up to 5 days was the highest in Angus breed and was the lowest in Red Dene .

^6

Table III shows by breed, the difference in percent of non-returns
between 1 ana 2, 2 and 3 , 3 and h, and between h and 5-day-old semen. The
percentages of non-returns are based on total current services (1 , 2, 3 ,
U, 5 and over) for the period of one year.

From the Table it can be

stated that in each breed there was a variation in the amount of decline
of percent of non-returns for day-to-day storage of semen.

For example,

in Red Dane, the percent of non-returns decreased 13.2 5% from 1 day to
2-day-old semen, 7 .28$ from 2 day to 3-day-old semen, 2 .12$ from 3 day to
It-day-old semen and U.65$ from ij. day to 5-day-old semen.

A wide variation

between breeds in the amount of decline of percent of non-returns for dayto-day storage of semen was also noted.

In Jersey, the decline of percent

of non-returns from 1 day to 2-day-old semen was U.82/b (6 6 .51-6 1 .69) and
that from 2-day to 3- day-old semen was 5.33$.

°n the other hand, in Red

Dane, the decline of percent of non-returns from 1-day to 2-day-old semen
was 1 3 .25$ snd that from 2-da.y to 3-da.y-old semen was 7.28%.
Table IV shows the yearly percent of non-returns for total current
services (l, 2 , 3 ,
age of semen.

5 and over) by breed irrespective (regardless) of

From the Table, it is clear that the yearly percent of non­

returns, regardless of age of semen, was the highest for Angus breed whereas
it was the lowest for Red Dane.

Holstein was the 2nd highest whereas

Jersey ranked the third highest in yearly percent of non-returns .

Statis­

tical analysis revealed highly significant differences (1$ level) in
yearly percent of nonreturns between Angus breed and Holstein, Angus
and Jersey, Angus and Guernsey and between Angus and Red Dane . Highly
significant differences (1$ level) in percent of non-returns were also

TIBLn III
DIFFERENCE IN PERCENT OF EON-RETURNS n O T E E N 1 AND 2, 2 AND 3,
3 AND I| ? A AND 5-D A Y -O L D SEKEN
(b y b r e e d )

Age of Semen in Days

Breed

1- 2
% W . R.

2-3
% N .R.

3 - h
% N.A.

h - 5
DR. K .

Holstein

-6 .UO

-6.99

-5.17

-o .65

Guernsey

-6.U5

-6.51

-A .06

-a l .314

Jersey

-U .82

-5.33

-3.03

-5.96

-13.25

-7 .26

-2.12

-h .65

-2 .25

-7 .3h

-3.29

-2 .21

Red Dane
Angus

TABLE IV
YEARLY PRECENT OF ftON-RETURNS BY BREED REGARDLESS OF AGE OF S M E N

Breed
Holst ein
Services

N.R.

Services

ftumber

Cf

Humber

123,379

Jersey

Guernsey

p

62.5?

h2,709

ft.R.
%
58.6ii

Services
Lumber

9,928

Red Dane
ft.R.
%

60.37

Services
Number
7,069

Angus

ft .R.
%
57 .02

Services

R.R.

Number

C‘
p

7,356

65.63

•t"
On

U9

noted between Holstein and Jersey, Holstein and Guernsey and between
Holstein and Red Dane.

Similarly, the difference in percent of non­

returns between Jersey and Guernsey and between Jersey and Red Dane was
highly significant (1# level) . There was also a highly significant dif­
ference (l$ level) in the yearly percent of non-returns between Guernsey
and Red Dane breeds.
Table V shows by breed, the yearly percent of total services (l, 2,
3, i), 5 a-nd over) for each age of semen.

From the Table it can be stated

that the yearly percent of total services for each age of semen in
Holstein and Jersey breeds was almost the same.

In Guernsey, the percent

of total services for each age of semen was nearly the same as in Holstein
and Jersey except that for 1-day-old semen, it was about 3 -

less.

In Angus and particularly in Red Dane, the percent of total services for
1-day-olc semen was markedly low as compared to other breeds . The percent
of total services for 2-day-old semen in these breeds was also low as com­
pared to other breeds.
Table VI shows the yearly percent of non-returns by age of semen in
days, regardless of breed.
Table VI.

Date for Angus breed are not included in

The percentages of non-returns are based on total current serv­

ices (1, 2, 3, h, 5 and over) to all females.

From the Table it is clear

that the percent of non-returns decreased as age of semen advanced.

The

decline in percent of non-returns from 1 day to 2-day-old semen, 2 day to
3-day-old semen „ 3 day to L-day-old semen, and from 5 day to 5-da.y-old semen
was 6.5U, 6.85, 5.t>6 and 0.70 percent, respectively.

Statistical analysis

revealed a. highly significant difference (l/t level) in the percent of

TABLE V
YEARLY PERCENT OF TOTAL SERVICES BY BREED FOR EACH AGE OF SEMEN

Age of Semen in Days
1___

Breed
Services
(Number)

Percent
of Total
Services

T

Services
(Number)

3

Percent
of Total
Services

Services
(Number)

%

5

Percent
of Total
Services

Services
(Number)

Percent
of Total
Services

Services
(Number)

Percent
of Total
Services

Holstein

29,190

2U.15

k8,k32

39.26

32,595

26.U2

10,730

6.70

1,832

l.k9

Guernsey

8 ,6lil

20.23

17,22k

Uo .33

11,695

27.38

h,3ok

10.22

765

l.ei

Jersey

2,28b

23.01

3,863

38.91

2,761

27.61

867

6.93

133

1.3h

Red Dane

285

U .02

2,521;

35.60

2,756

38.88

1,290

18.20

238

3.30

A.ngus

936

12.72

2,706

36.60

2,291;

31.16

1,167

15 .86

253

3.hh

TABLE VI
YEARLY PERCENT OF NON-RETURNS BY AGE OF SEMEN REGARDLESS OF BKEED (DAIRY)

Age of Semen in Davs
V
1
Services
Number

1*1,000

2
N ,R.
%

69.59

Services

a .R

Number

fit

72,01*3

h

3
.

/o

63.05

5

Services

N.R.

Services

L.R.

Services

K.K.

Number

Prr

Number

a'o
/

Number

d

1)9,807

56.20

17,271

51A

2,981)

50.81)

Vn

H

52

non-returns between 1-day and 2-day-ola, 2 day and 3-day-old, and between
3-day and U-day-old semen.

The difference in percent of non-returns be­

tween U-day and 5-day-old semen was not statistically significant
level) .
The over-all yearly percent of non-returns on total current services
(l, 2 , 3 , U, 5 ajn-d over), for dairy bulls under study was 61 .k%, whereas,
it was 6 1 S 3 % Tor all bulls, including beef bulls.
Table VII shows by breed, the percent of non-returns on total current
services (l, 2 , 3, U, 5 and over), by month of breeding, regardless of age
of semen.

From the Table, it can be seen that for Holstein breed, the

percent of non-returns was the highest in October.

The percent of non­

returns was also high in September as compared to other months.

Ma.y was

found to be the month of lowest percent of non-returns for Holstein.
Statistical analysis showed a. highly significant difference (1% level) in
percent of non-returns between October and May.
In Guernsey breed, the percent of non-returns was the highest in
September.
months.

It was also high in April and October as compared to other

The percent of non-returns was lowest in August.

The difference

in percent of non-returns between September and August wa.s hig'lily signifi­
cant

level).
In Jersey breed, the percent of non-returns was highest in April and

was also higher in October and September as compared to other months.
The percent of non-returns was lowest in August.

The difference in per­

cent of non-returns between April and August was highly significant

{1% level).

TABLE VII
PERCMT OF NON -BETURtiB BY BLEED BY h OKTH REGARDLESS OF AGS OF S3IEN

of
Breeding

Holstein
Number
Services
K

u/

.

R

.

Guernsey
Number
Services
h.

R

.

Jerse J
Number
Services

0/
p

N

.R.

Red Dane
rj
Humber
P
Services
N.R.

Angus
or
Number
Services
N.H.

J snuary

12,763

60 .36

3,893

39.36

1,088

61.21

871

93.29

911

62.13

February

11,376

62.07

3,967

37.93

1,136

97.99

726

88.30

923

65.55

March

11,692

63.26

3,399

39.03

769

38.92

681

87.30

995

68.90

April

11,366

62.81

3,206

61.29

932

66.92

628

62.10

770

75.19

May

13,918

60.29

3,536

38.01

1,136

87.16

891

83.86

937

67.66

June

12,139

62.27

3,199

38.80

1,000

88.30

82 9

87.06

166

60.23

July

10,219

62.38

3,060

36.63

862

88.90

799

86.95

232

63.60

August

6,163

63.lo

3,371

36.38

601

85.87

336

82.06

372

63 .33

September

7,280

65.k9

2,993

61.33

603

69.30

319

86.60

206

87.77

October

7,397

66.97

2,919

60.90

600

66.80

3 6
0

63.29

306

62.81

November

7,286

63.18

2,396

89.87

3-30

63,11

310

83.19

539

63.38

December

9,616

62.03

2,932

88.73

600

89.30

523

33.68

931

61.58

\n

5k

In the Red Dane breed, the percent of non-returns was the highest
in October and was also high in April compared to other m o n t h s .
percent of non-returns was the lowest in August .

The

The difference in p e r ­

cent of non-returns between October arid August was highly significant
(1/6 level) .
For the Angus breed, the percent of non-returns was the highest in
April and was the lowest in September.

The difference in percent of

non-returns between April and September was highly
■Table VIII shows the difference in percent

significant (1)6 level) .

of non-returns between

1 and 2 da.y, 2 and 3 day, 3 and U-da.y-old semen for the month of highest
(October)

and lowest (May) breeding efficiency (percent of non-returns)

in the Holstein breed.

The percentages of non-returns are based on total

current services (l, 2, 3 , k, 5 and o v e r ) .
services for 5-day-old
percent of

The number of total current

semen was less and hence the amount of decline in

non-returns from l|.-da.y to 5-day-old semen is not shown in

Table VIII.
From the examination of Table VIII, it can
of decline in percent of non-returns from 1

day

be stated that the

amount

to 2-day-ola semen was

U .82)6 (8.33 “ 3.5l) greater in Ma y than that in October.

However, the

amount of decline in percent of non-returns from 2 day to 3 -da;y-old semen
in October

and M a y was about equal. Similarly, the amount of decline

in

percent of

non-returns from 3 day to ^-day-old semen in October and May

was nearly the same.
Table IX shows by breed, the percent of non-returns on total current
services (l, 2 , 3 , U, 5 and over), b y season of breeding, regardless of
age of s e m e n .

5'5

TABLE VIII
DIFFERENCE IN PERCENT OF NON-RETURNS BETWEEN 1 AND 2, 2 AND 3,
3 AND 1}-DAY-OLD SEMEN FOR hONTII OF HIGHEST AND LOWEST
BREEDING EFFICIENCY IN HOLSTEIN BREED

Age of Semen In Days
Month of
Breeding

October

1 - 2
)0 K . R .

-3 .5 1

2 - 3
% io . R .

-6.70

3 - k
% N . R.

- 5 .ii6

TABLE IX
PERCENT OF NON-RETURNS HI BREED BY SEASON REGARDLESS OF AGE OF SH'IEN

Season
of
Breeding

Breed
Guernsey

Holste in
Number
Services

'b

N .R.

P
P

Number
Services

N .it.

Number
Services

Angus

Red Dane

Jersey

%
N.R.

Number
Services

C'
P

N.R.

Number
Services

d
p

N.R.

Fall

22,063

65.23

7,970

60.69

1,766

65.36

1,135

58.77

1,161

62.70

Winter

33,859

61 .65

10,802

58.67

2,836

59.39

1,620

56.06

2,765

63.07

Spring

36,696

62.01

11,207

59.27

2,867

60.59

2,170

57.70

2,662

70.29

Summer

30,561

62.57

12,730

57.65

2,683

57.71

1,966

56.16

770

63.12

57

In Figure 2 is shown by bre e d , the effect of season of breeding on
the percent of non-returns (regardless of age of semen) based on total
current services (l, 2 , 3 , U, 5 and over).
From Table IX and Figure 2, it is clear that for Holstein breed, the
percent of non-returns was the highest in fall end was the lowest in
winter season.

Statistical analysis of the data revealed that the dif­

ference in percent of non-returns between these two seasons was highly
significant (1 % level).

Highly significant differences (l% level) in

percent of non-returns were also noted between winter and summer and be­
tween fall and spring seasons.
In the Guernsey breed, the percent of non-returns was the highest
in the fall and was the lowest in summer.

Statistically, the difference

in percent of non-returns between the fall and. the summer was highly
significant

level) . There was no significant difference ($% level)

in percent of non-returns between winter and summer.
In the Jersey breed, the percent of non-returns was the highest in
fall and was the lowest in summer.

The difference in percent of non­

returns between fall and summer was highly significant O S level) .
In the Red Dane breed, the percent of non-returns was the highest
in.faLl and was the lowest in winter season.

However, the difference in

percent of non-returns between fall and winter was not statistically
significant (5a> level) .
In the Angus breed, the percent of non-returns was the highest in
spring and was the lowest in fall.

The difference in percent of non-returns

between spring and fall was highly significant (1% level) .

lhere were no

58
Holstein
Guernsey
Jersey
.......
*

n—

Red Dane
Angus

Percent of Non-Returns

70

65

60

Fall

Winter

Spring

Season of Breeding

Fig. 2.

The effect of season of breeding on the percent of
non-returns (regardless of age of semen).

59

significant differences (5/6 level) in percent of non-returns between
summer and fall and between winter and f a l l .
Table X shows the difference in percent of non-returns between 1 and
2-day, 2 and 3~day and between 3 and l|.-day-old semen for the season of
highest (fall season in both the breeds) and lowest (winter in Holstein,
summer in Guernsey) breeding efficiency (percent of non-returns) in
Holstein and in Guernsey breed.

The percentages of non-returns are baaed

on total current services (1, 2, 3, b, 5 and over) .

The number of total

current services for 5 -da.y-old semen was less and hence the amount of
decline in percent of non-returns from b day to 3-day-old semen is not
shown in Table X.
From the examination of Table X, it can be stated that for Holstein
the amount of decline in percent of non-returns from 1 -day to 2-day-old
semen was 0 .U5/6 (o .Hi-5.69) greater in winter season than that in fall
season.

Similarly, the decline in percent of non-returns from 2-day to

3-da.y-ola semen was 0 .73/6 greater in winter, whereas, the decline in
percent of non-returns from 3 -day to U-aa.y-old semen was 2 .26/6 greater
in winter than that in fall season.
For Guernsey breed, the amount of decline of percent of non-returns
from 1 -da.y to 2-day-old semen was 0 .93/6 greater in summer season than
that in fall season.

Similarly, the decline in percent of non-returns

from 3 -day to I|.-d.ay-old semen was 3.82/6 greater in summer than that in
fall.

On the other hand, the amount of decline in percent of non-returns

from 2-day to 3-day-old semen was 2 .79% less in summer than that in fall
season.

60

TABLE X
DIFFERENCE IN PERCENT OF NON-RETURNS BETWEEN 1 AND 2, 2 AND 3,
3 AND 1+-DAY-0LD SEMEN FOR SEASON OF HIGHEST AND LOWEST
BREEDING EFFICIENCY

1 - 2
% N. R.

• i

A.ge of Semen in Days
Season
of
Breeding

2 - 3
% N.R.
(A) Holstein Breed

Fall

•5'.69

-6.5U

-3.H

Winter

-6 .ll|.

-7.27

-5.37

(B) Guernsey Breed
Fall

Summer

5.60

-8.6U

-2 .20

-6.53

-5.85

-

-

6.02

ol

Ta.ble XI shows the yearly percent of non-returns based on first
current services for 1 -aay-old semen in the registered and non­
registered females .
Statistical analysis of the data presented in Table XI, s ho vied a
highly significant difference (l$ level) in the percent of non-returns
between registered and non-registered females in favor of registered
females . The weighted average of percent of non-returns with 1-day-old
semen was 10.9% (79.36 - 6 8 .U 6) greater for the registered females than
for the non-registered females .
In Table XII are presented the mean and distribution (standard devi­
ation) of total current services (1 , 2 , 3 , h, 5 s-ad over), by breed, for
each date of semen collection for a bull.

The mean of total current

services for each date of semen collection for a. bull was the highest in
Holstein breed and was the lowest in Jersey breed.

(D)

Discussion

Willett et al. (19J4O) reported that with proper precautions in
handling the semen and diluent, the percent of non-returns resulting from
diluted semen stored up to h days is as satisfactory as that obtained
with semen used on the day of semen collection.

According to Henderson

(19U 6) with good quality semen that is properly cooled and diluted, no
significant decrease in fertilizing capacity should result up to h days
of storage.

Anderson (19U3) reported that conception rate from the use

of semen stored- up to 72 hours was equal to that of fresh semen.

62
TABLi XI
YEARLY PERCENT OF EON-RETURNS FOR 1 -DAY-OLD SEMEN
IN REGISTERED AND NON-REGISTERED FEMALES

Registered Females
Services
N.R.
Number
%

106
107
111
113
115

116
117

121
122
123

126
127
128
130
131
135
136
11*0
iU
1U3
ibb
1U5
1U7
151
152

156
157
158

160
161
163
16U

83
26
35
h2
81
52
30
171
78
33
37
29
105
29
53
79
111
31
27
151
181
b7
50
32
130
U6
86
91
bo
53
100
7U

81
73
83
83
78
85
73
79
76
67
eh
62
77
76
81
70
7b
68
69
81
8JU
77
68
75
85
91
80
66
83
87
88
89

Non-Registered Females
Services
N.R.
Number
%
325
255
237
367
583
230
22 9
811
82 b
267
378
300
581
830
217
266
615
172
326
918
1,009
25U
U23
2 60
7U7
338
68b
701
2U3
U83
709
UIiO

69
71
7b
71
72
69
69
71
61
81

69
59
67
72
53

72
70

76
70
68
66
69
70
73
70
67
70
61
70
67
67
67

girted

rage

79.36

68.i

TABLE XII

MEAN AND DISTRIBUTION OF TOTAL CURRENT SERVICES FOR EACH DATE OF
SEMEN COLLECTION FOR A BULL
(31 BREED)

Breed
Holstein
*♦

Guernsey

Jersey

Red Dane

Angus

1302

756

2k7

lli2

123

Mean

95

57

kl

50

59

Std. Deviation

hi

31

20

19

26

K

Number of items or frequency.

Erb

ftk* (!950) reported that the average of percent of non-returns

with 1-day-old semen was equal to that of 2-day-old semen.
The results obtained in the present investigation do not agree
with the results reported (mentioned above) b y Willett et a l . (I9I4O) ,
Henderson (19^4-6) , Anderson (19^5) and by Erb et al. (1950) .

Our results

confirm the findings of Schultze et al. (19I48) , Schaefer (19148), and those
of Sweetman (1953) in that the over-all percent of non-returns decreased
as age of semen advanced.

However, the amount of decline in percent of

non-returns for day-to-day storage of semen was somewhat higher than
that reported b y these investigators.
In the present study, a great variation in the fertility (percent
of non-returns) of bulls was observed.
ported b y White et. al. (1925)

The result agrees with that r e ­

and Miller and Graves (1932) . Bulls were

found to vary -widely in the amount of decline of semen fertility (percent
of non-returns) for day-to-day storage of semen.

The result is in agree­

ment with that reported by Schultze et al. (I9l|8) and Swanson (1951) .
From the data presented in Table I, it can be seen that in bull 126, the
amount of decline in percent of non-returns (fertility) from 1-day-old
to 2-day-old semen, 2-day-old to 3~day-old, 3-day-old to H-day-old semen
was 1, 5 and 11 percent, respectively.

In bull 125, the amount of decline

in percent of non-returns from 1-da.y-old to 2-day-old semen, from 2-dayold to 3-day-old semen was 10 and 10 percent, respectively.

The results

quoted above suggest that in bull 126 or in bulls showing similar decline
of percent of non-returns for day-to-day storage of semen, efforts should
be made not to use semen which is more than 2 days or 3 days old.

On the

65

other hand, in bull 128 or in bulls showing similar decline of percent
of non-returns for day-to-day storage of semen, efforts should be made
to use semen as fresh as possible in order to secure higher percent of
non-returns.
Schultze _et al. (19^.8) reported that the over-all percent of non­
returns for Guernsey breed was greater than that for Jersey breed.

Erb

et al. (1950) found no difference in percent of non-returns for Holstein
and Guernsey.
non-returns.

However, Jersey was found to have the lowest percent of
Mercier and Salisbury (19U7) reported that the Guernsey

bulls had a slightly higher fertility (percent of non-returns) than the
Holstein-Friesian bulls.

The results obtained in the present investiga­

tion do not agree with the results reported by Schultze et al. (19U8) ,
Erb et a l . (1950) and Mercier and Salisbury (19U?).

On the contrary, our

results confirm the findings of Mercier and Salisbury (19^6) and Lewis
(19U8b) in that the percent of non-returns for Holstein breed was greater
than'that for the Guernsey breed.

However, the difference in percent of

non-returns between Holstein and Guernsey was much less than that reported
by these investigators.
The yearly over-all (regardless of age of semen) percent of non­
returns for Red Dane breed, in the present study, was the lowest of all the
breeds (dairy and beef type) even though the percent of non-returns with
1-day-old semen was the highest in Red Dane.

This might be attributed to

some exbent to the fact that the percent of total current services for
1-day and for 2-da.y-old semen was the lowest in Red Dane as compared to
ary other breed under study.

Moreover, our results, presented in Table III,

66

showed that, the amount of decline of yearly percent of non-returns from
1-day-old semen to 2-day-old semen was the largest (13.25$) in Red Dane
as compared to other breeds.

Hen c e , in order to obtain higher percent

of non-returns, efforts should be made in Red Dane breed in particular,
to use the semen as fresh as possible for breeding the females.
In Angus breed, the amount of decline in semen fertility (percent
of non-returns) from 1-da.y-old semen to 2-d.ay-old semen was 2 .25$ whereas
the amount of decline in percent of non-returns from 2-day-old semen to
3-day-old semen was 7.3U$.

The results suggest that much higher conception

rate (percent of non-returns) with Angus bulls could be secured by using
semen wliich is 2-day-old or less than 2-day-old.
Of all the breeds under study, the breeding efficiency (percent of
non-returns) was the highest in Angus breed.

This, to some extent, might

be due to greater ability of Angus breed compared to other breeds, to
maintain the fertility of semen (percent of non-returns) during storage
for U or 5 days (Table III) .
Lewis (l9U6a) noted that the breeding efficiency (percent of non­
returns) in Holstein bulls was the highest in March and April and was the
lowest in December.

In Guernsey, the percent of non-returns was the

highest in November and lowest in July.

The percent of non-returns in

Guernsey was also high in October and March.

Our results for Holstein

breed showed that the percent of non-returns regardless of age of semen,
was the highest in October and was the lowest in May.

In Guernsey breed,

the percent of non-returns was the highest in September and was the lowest
in August.
.fill®

67

Lewis (I9h8a) found tha.t the percent of non-returns for Holstein
breed was much higher during spring season as compared to other seasons.
The percent of non-returns was the lowest in summer.

However, the per­

centages-of non-returns in summer (6 U.i$) and in winter (6 U. 5 #) for
Holstein were almost equal.

In Guernsey, the percent of non-returns was

the highest in fall and was the lowest in winter.

However, the percentages

of non-returns in winter (5 7 .8/a) and in summer (5 7 .9 $) were almost equal.
In the present study, the percent of non-returns (regardless of age
of semen) for the Holstein breed was the highest in fall and was the lowest
in winter.

The difference in percent of non-returns between winter and

summer seasons was highly significant (1% level). A highly significant
difference (l% level) in the percent of non-returns was also noted between
fall and spring seasons in Holstein.

In Guernsey breed, the percent of

non-returns (regardless of age of semen) was the highest in fall and was
the lowest in summer.

However, the difference in percent of non-returns

between summer and winter seasons was not statistically significant
(5 /° level) .
In the present investigation, the weighted average of percent of non­
returns with 1 -day-old semen was 10.9% greater for registered females
than for non-registered females.

Statistical analysis revealed a highly

significant difference (.1 % level) in the percent of non-returns between
registered and non-registered females .

The higher percent of non-returns

in registered females might be due to better management of the registered
females . Poor management of the herds has been reported to affect adversely
the conception rate. '(Dickensheet et al. 19U9) .

Attempt was made to find out whether the difference in percent of
non-returns between registered and non-registered females with 1 -day-old
semen was due, in part, to more use of fresh semen in the registered
females .

The breeding da.ta showed that the percent of total services

with 1 -day-old semen was 2 6 .14$

in registered females as against 2 h. 9 S$

in the non-registered females.

Thus, the use of 1-da.y-old semen in the

registered females was somewhat greater than that in the non-registered
females.

However, the difference in percent of total services with

1 -da.y-old semen in registered and non-registered females was not statis­

tically significant (5$ level) .

Similarly, the percentages of total

services with 2 -da.y-old semen in registered (3 9 .3 !$) 2nd in non-registered
females (39.U3/0 were almost equal.

The results indicate that factors

other than' a.ge of semen, such as better feeding and better management
(care, disease control, etc.) might be responsible for the higher percent
of non-returns in registered females as compared to that in nonregistered females .

(E)

SlMfiARY AND COhCLUSIONS

The breeding records of dairy a.nd beef bulls of Micliigan Artificial
Breeders Association were analyzed starting from the current service uate
of June 1, 1951

June U, 1952, in order to study the influence of

various factors on percent of non-returns.

The factors studied were age

of semen, bull, breed, month and season of breeding, registered and nonregistered females in relation to percent of non-returns.

The percentages

69

of non-returns were based on 9 0 -day non-returns of all females witli 1 , 2 ,
3, U, 5 and over services except in the study of registered and nonregistered females, the percentages of non-returns were based on 1 st
service females owing to unavailability of data for 2 , 3 , h 5 and over
services to registered females.

The investigation led to the following

findings and conclusions:
(1) Influence of Bull
In general, the yearly percent of non-returns for both dairy and
beef bulls decreased as age of semen advanced from 1 to 5 days.

Ilence,

semen should be used as fresh as possible in order to secure higher percent
of non-returns.
Bulls varied widely in the amount of decline of percent of non-returns
for day-to-day storage of semen.

A wide variation was also noted be'tween

bulls in the average daily decline of percent of non-returns up to 5 days
of storage of semen.

There was a great variation in over-all (i. e.,

regardless of age of semen) yearly percent of non-returns between bulls
within a. breed.

(2 ) Influence

of Breed

The yearly percent of non-returns in Holstein, Jersey, Red Dane, and
Angus breed, declined as the age of semen advanced from 1 to 5 days.
Similar finding was also noted in Guernsey breed except that the percent
of non-returns for 5 -day-old semen was slightly higher (statistically not
significant) than that for lj.-day-old semen.
There was a wide variation between breeds in the average daily de­
cline of percent of non-returns during storage of semen for 5 days.

The

70

a.vera.ge daily decline of percent of non-returns up to £ days of semen
storage was the highest in Red Dane, whereas, it was the lowest in Angus
breed.

In ea.ch breed there was a variation in the amount of decline of

percent of non-returns for day-to-day storage of sem e n . A wide variation
between breeds in the amount of decline of percent of non-returns for
day-to-day storage of semen was also noted.

The decline of percent of

non-returns for 1-day to 2-day old semen was the highest in Red Dane
whereas it was the lowest in Angus.

Of all the breeds under study, the

yearly percent of non-returns, regardless of age of semen, was the highest
for Angus breed and the lowest for Red Dane.

Holstein ranked the second

highest in yearly percent of non-returns, whereas Jersey ranked the third.
(3 ) Influence of Percent of Total Services for Each Age of Semen
In Red Dane, the percent of total services for 1-day old semen was
markedly low compared to other breeds.

This might, in part, explain the

lowest percent of non-returns observed in Red Dane.
(I4) Oyer-all Yearly Percent of Non-returns Regardless of Breed
The over-all yearly percent of non-returns on total current services
Cl, 2, 3, h, 5 and over), for all bulls under study was
(5) Influence of Month of Breeding
For Holstein and Red Dane breeds, the percent of non-returns was the
highest in October.

For Jersey and Angus, the percent of non-returns was

the highest in April whereas for Guernsey, the percent of non-returns was
the highest in September.
For Holstein, the percent of non-returns was the lowest in May.

For

Guernsey, Jersey and Red D a n e , the percent of non—returns was the lowest
in August whereas for Angus, it was the lowest in September.

71
t

(6) Influence of Season of Breeding
In all the dairy breeds under study, the percent of non-returns liras
the highest in fall season whereas in beef breed (Angus), it was highest
in spring.

For Holstein and Red Dane, the percent of non-returns was the

lowest in winter whereas for Guernsey and Jersey, it was lowest in Summer.
In Holstein, the amount of decline of percent of non-returns from
1-day to 2-day, 2-day to 3-day, 3-day to li-day-old semen was greater in
season of loxtfest percent of non-returns (winter) as compared to season
of highest percent of non-returns (fall) .
(7) Influence of Registered and Non-registered Females
The weighted average of percent of non-returns with 1-aay-old semen
was 1 0 .9% greater for first service registered females than for first
service non-registered females.
(8) Number of Females Inseminated with a. Day's Semen Collection for a Bull
The number of females inseminated with the semen obtained from a day's
collection for a bull was the highest in Holstein breed (95 females) and
was the lowest in Jersey breed (111 females) .

72

INTER-RELATIONSHIP OF CERTAIN .SEMEN CHARACTERISTICS AND RELATIONSHIP
BETWEEN VARIOUS SEMEN CHARACTERISTICS AND PERCENT OF NON-RETURNS

(A) REVIEW OF LITERATURE

According to Davis (1938) initial motility of the spermatozoa, is one
of the best, if not the best, single evidences of viability of semen.
Davis and Williams (1939) in a study on dairy bulls found a slightly
significant correlation between volume of semen and initial motility of
spermatozoa, volume of semen and concentration of spermatozoa per cubic
mm., and between percentage of motility (initial) of spermatozoa and con­
centration of spermatozoa per cubic mm.

Motility in this study was

expressed as percentage of spermatozoa showing progressive motion.
Anderson (l9Uo) found that infertile bulls produced less volume of
the ejaculate.
Dougherty and Evalt (19iil) reported little correlation of initial
motility of sperm, percentage of abnormal spermatozoa and concentration,
with breeding efficiency.
Swanson and Herman (l9Ula) in a study of semen from 10 dairy bulls
used in the University of Missouri dairy herd reported that semen volume,
concentration, pH of semen, percentage of abnormal spermatozoa and initial
motility of spermatozoa were not correlated with the fertility of the
b u l l . The semen characteristic most nearly correlated with fertility was
the length of survival with vigorous motility when the semen was stored
undiluted at U0°F. When separate ejaculates from the same bull were
considered, initial motility was found to be roughly correlated with

73

viability in storage.

Pregnancies, in this study, were determined by

examination and by failure of the cows to come in heat after service.
In the study of semen from Arizona range beef bulls , Lasley and
Bogart (19U3) found no significant correlation of semen volume with con­
centration, initial motility rating, abnormal spermatozoa, percentage
live spermatozoa in semen immediately after collection.

Concentration

of spermatozoa was highly correlated with initial motility rating but
was negatively correlated with the percentage of abnormal spermatozoa.
Motility (initial) rating was significantly correlated with the per­
centage of live spermatozoa immediately following collection.
Ejaculates containing larger amounts of semen were found to give
the greatest fertility.

Concentration of spermatozoa and the number of

spermatozoa per ejaculate were highly correlated with fertility.

The

correlation between concentration of spermatozoa and fertility was
curvilinear (concave type) in that the ejaculates containing 800,000 to
1,000,000 sperm per cubic millimeter gave the lowest fertility x-zhereas
ejaculates of lower and higher concentration gave greater fertility.
Initial motility rating and the percentage of abnormal spermatozoa, were
not significantly correlated with fertility.

Semen containing less than

50 percent live spermatozoa immediately following ejaculation, was of
questionable fertility.

But semen samples containing %0-90% of live

spermatozoa, varied little in fertility.
The number of spermatozoa, per insemination was significantly corre­
lated with fertility.

The number of live spermatozoa used per insemi­

nation was more closely related to fertility than the total number of
spermatozoa.

7U

In this study all the semern samples were given an initial motility
rating of 2 or over 2.
Margolin et al. (19U3) reported a. significant correlation between
longevity (duration of motility) of diluted semen samples stored in a
refrigerator at U5°F and the conception r a t e .

Conception was ascertained

by palpation or by the calving of the cows served.
Lasley (19UU) found a highly significant correlation between live
and percentage of motile spermatozoa, and between live and progressively
motile spermatozoa in non-stored semen.

Furthermore, a. correlation be­

tween the percentage of motile spermatozoa and fertility was also noted.
The percentage of live spermatozoa in tiiis study was determined by
the opal blue-eosin staining method.
Swanson and Herman (19^U) reported that concentration of sperm,
abnormal sperm and pH of semen of dairy bulls were not significantly
correlated with conception r a t e .

Conception was determined either by

calving, manual examination for presence of fetus or by failure of cow to
return to heat within 90 days after insemination.
A highly significant linear correlation between viability of the
sperm in storage and conception rate was found.

There was also a signifi­

cant curvilinear (convex type) relationship between motility rating of
semen at the time of insemination and conception r a t e .

With the increase

of motility rating up to rating of 3, conception rate increased but with
further increase in motility rating, conception rate showed, a nonsignifi­
cant increase.

75

Ladng (19^5) found that bulls of higher fertility gave on the average
more volume of semen than bulls of lower fertility.

Laing suggested that

although the fertility is adversely affected if a minimum requirement in
quantity and quality of spermatozoa is not met, factors other than semen
quality are in operation within the range of fertility from 1.0 to 3.5,
which may vary breeding results irrespective of quality of semen.
Fertility in this study was measured by the number of services per
conception based on diagnosis of pregnancy by rectal examination at about
50 days from the date of last serv i c e .

Mercier and Salisbury (19U6) in an analysis of the combined data for
the ejaculates of Holstein and Guernsey breed found highly significant
correlation of concentration of spermatozoa with percent of non-returns.
Percentage of abnormal spermatozoa and methylene blue reduction time were
significantly correlated with percent of n on-returns.
Ellenberger and Lolimann (191+6) found that volume of ejaculate, con­
centration of spermatozoa., total number of spermatozoa per ejaculate of
dairy bulls were not significantly correlated with conception r a t e . These
investigators believed that there was little to be gained by continuing
observations on duration of motility in storage beyond periods of from
3 to 7 d a y s .
Madden et al. (191+7) in a study on dairy bulls reported s. highly
significant correlation between initial motility and initial percentage
of live sperm.

However, this relationship was fairly variable.

These

investigators found no significant differences in the initial motility,

76

initial percentage of live sperm or longevity- in storage between semen
samples which resulted in conception and samples which did not.
Lewis (I9b8a) in a study on dairy bull semen found a significant
correlation between semen volume and initial motility (percent of pro­
gressively motile spermatozoa) for Holstein bulls but correlation for
Guernsey bulls was not statistically significant.

Correlations between

concentration and initial motility were highly significant for the
Guernseys but were not significant for the Holsteins .

Semen volume, con­

centration, total spermatozoa per ejaculate or initial motility of the
semen shipped was not significantly correlated with percent of non-returns.
Percent of living sperm determined with eosine-aniline blue staining
method was reported by Schaffer and Almquist (19^9) of having a highly
significant curvilinear regression with percent non-returns.

However, the

predictive value with relatively high quality semen was questionable.
Ludwick et al. (19ii8) using semen samples bred to 30 or more cows
obtained a high correlation (r = 0.8b ± 0 .0 3 ) between incubation time
(time for sperm to lose all activity when held at 100° F) and percent of
non-returns.

However, the correlation was lowered considerably when semen

samples bred to fewer cows were used.
Erb et a l . (1950) reported that a minimum of 30, first and second
services were required before the conception rate (percent of non—returns)
of a single semen sample could be accepted as a. reasonable approximation
of its fertilizing capacity.

These investigators found no significant

relationship of initial motility, concentration of sperm or initial pH
with fertilizing capacity of semen from dairy bulls with acceptable breeding

a

77

efficiency.

The correlation of the percentage of sperms alive at the

time of semen collection and the fertilizing capacity was highly signifi­
cant.

Motility for each day of storage up to 6 days showed a highly

significant correlation with percent non-returns.

The correlation between

initial motility and concentration was highly significant.
Branton et al. (I9$l) in an analysis of semen quality and breeding
results of 100 semen samples found no significant correlation of initial
motility of spermatozoa with percent of non-returns. But there was a
highly significant correlation between concentration of the individual
ejaculates with percent of non-returns.

A still greater highly significant

correlation was observed when the analysis was based on the means for the
individual bulls . The numbers of motile spermatozoa per milliliter of
diluted semen or per insemination showed a highly significant correlation
with percent of non-returns.
Table XIII shows the correlation between semen characteristics re­
ported by various investigators. Table XIV shows the correlation of semen
characteristics with conception rate or percent of non-returns reported
in the literature .

(B)

EXPERIMENTAL PROCEDURE

Semen collection records (Standard Card No. 2) for bulls of various
breeds, namely, Holstein, Guernsey, Jersey, Red Dane and Angus were used
to find the arithmetic mean and standard deviation for various semen
characteristics, by breed and regardless of dairy breed.

The semen

TABLE U I I

CORRELATION BETWEEN SEMEN CHARACTERISTICS

Correlation Between

Davis et al.
(19397
r
(Pearson)

Lasley et al.
(I9J4.3T
I'j
r

U76

-0.035

Semen volume and abnormal - spermatozoa

176

-0.006

Semen volume and percentage of sperms alive
in non-stored semen

22ii

+0.075

Semen volume and sperm - concentration

22I4

+0.3353"

Semen volume and progressive motility of
sperms of non-stored semen

22h

+O.378f

Sperm concentration and progressive motility
of sperms of non-stored semen

26k

Lesley
(19UU)
N

r

+0 .3095*

Progressive motility of sperms in non-stored
semen and percentage of sperms alive in
non-stored semen
+ Number of samples used in calculating the coefficient of correlation (r)
* Significant at % level of probability
Significant at 1CJ> level of probability

156

+0.696**

TABLE XIV
CORRELATION OF SHMEN CHARACTERISTICS WITH CONCEPTION RATE OR PERCENT OF NON -RETURNS

Lasley et al.
(l9ii3T

Swanson et al. Hercier et al.
. (19WJ“
(19W

Erb et al.
(19^0)

Branton et a l .
(wbT

r

N

40.162"'' 590

40.031*

100

Initial motility of
sperm (non-stored
semen)

187

+0.136

Percentage of sperms
alive (non-stored
semen)

198

J/-5£+0.212"

373

+0.002

187
187

+0 .335:.
+0.317'*“

iM+
Semen volume
Sperm concentration

303

r

N

r

40.909**
559

+0.63

pH

205 -0 .18

Percent abnormal sperm

525

Viability in storage

1*75 hO.SIT**

-0.12

IP

r

330

-0.033

328

2 60

-0 .13/

Motility of sperm in
semen stored:
for 3 days
for It days
N o , of sperm per
insemination

316

N

-0.096

+ Number of samples used in calculating the coefficient of correlation (r).
* Significant at $% level of probability.
Significant at 1% level of probability.

r

+0 .2831***

80

collection and breeding data of dairy b u l l s , (regardless of dairy breed)
were then subjected to correlation analysis so as to find the inter­
relationship between various semen characteristics and the relationship
of semen characteristics with percent of non-returns.

The non-return

rates (percent of non-returns) were based on 9 0 -day non-returns of
females with 1, 2, 3, b, £ and over current services regardless of age
of semen.

In view of the results reported b y Ludwick et al. (19148),

Erb £t al. (1950) , only the semen samples bred to I4O or more females
were used to determine the correlation of semen characteristics with per­
cent of non-returns. Howev e r , no such restriction of the number of
services, was placed in determining the correlation between various semen
characteristics

(C)

RESULTS

Table XV shows the arithmetic mean and standard deviation (distribu­
tion) for various semen characteristics of dairy bulls.

In this Table

are also shown by breed (dairy and beef) the arithmetic mean and the
standard deviation for certain semen characteristics, namely, semen
volume, sperm concentration, percentage of sperms alive in non-stored
semen and progressive motility of sperms in non-stored semen.

The raw

semen movement for Angus bulls is also included in the Table .

From the

Table, it can be seen that in dairy breeds, the semen volume was the
largest in Guernsey and was the smallest in Jersey.

Concentration of

semen (sperm concentration) was highest in Jersey and it was lowest in

TABLE XV

iEAh AND STANDARD d d v i ;ALTON FOR SiliEN eli-tAACT MRI ST'ICS

Breed

i.O . Of
Samples

Semen Volume
(mis .)
Std. Dev.
I-Iean

Sperms Alive in
Progressive I■otility of
Sperm Concentration
ilon-Sto red Semen % Snerm in bon--Stored Semen %
(per 1/1000 mm3 .)
Std. Dev . Mean
Std. D ev. Me an
Std. Dev.
i-lsan

Holstein

130) i

6.9

2.11

1667

373

73.2

3.63

60.5

U.69

Guernsey

779

7.2

2.26

1727

397

7 2 .S

3.50

80.6

3.UG

Jersey

2Up

5 .6

1.73

lo69

360

73.0

U.2U

30.6

3.69

Red Dane

IU2

6.2

1.U5

16 66

3c>

73.5

3.58

60.9

U .11

2U70

y <
O .L-

2.U7

1625

3oo

73.1

3.65

80.6

U.21

123

5.3

1.30

1651

UU3

71 .0

5,9U

79.7

3-37

Dairy bul‘
J1
i.—O
(average)
Ingas

ha.w Semen movement
I-iean
Lair;/- bulls

120h

L.O

iiRUlG Pulls

77

61. 9

Std. Dev.
9.9

3-Da.y-Old" Re-examined Semen

U-Dav-Old Re-examine'! Semen

Progressive Kotilitv of Soerm

Sperms H i v e
;-j

ox
Samples

i.O.

Lair ,- bulls

ooO
*

2n

39.0

Sod. Dev.

bo. of
Sample;
G30

mean

3.6.5

Semen sample re-examined 72 hours after collection.

Progressive Motility
of So erra >

Std .Dev . bean

o.o

33.9

S bd . Dev.
9.3

82

Guernsey.

However there was not much difference between dairy breeds in

the percentage of sperms alive in non-stored semen and the progressive
motility of sperms in non-stored semen.
The semen volume, sperm concentration, percentage of sperms alive in
non-stored semen and the progressive motility of sperms in non-stored
semen were greater in dairy bulls than in the beef bulls (Angus) .

However,

the raw semen movement in dairy bulls was slightly less than that in beef
bulls.
The percentage of sperms alive in U-day-old re-examined semen and
the progressive motility of sperms in 3-day- and U-day-old re-examined
semen showed a marked decline as compared to fresh semen examined soon
after the collection.
In Table XVI are presented the r-velues (coefficient of correlation)
for the correlation between semen characteristics of dairy b u l l s .

From

Table X V I , it can be seen that there were highly significant (1% level)
positive correlations between the following pairs of semen characteristics:
concentration of semen and percentage of sperrns alive in non-stored semen;
percentage of sperms alive in non-stored semen and progressive motility
of sperms in non-stored semen; raw semen movement and concentration of
semen; raw semen movement and percentage of sperms alive in non-stored
semen; raw semen movement and progressive motility of sperms in non-stored
semen.
Highly significant (1/5 level) negative correlation was noted oetween
volume of semen and concentration of semen and between volume of semen and
percentage of sperms alive in non-stored semen.

TABLE XVI
CORRELATION BETWEEN S H O T CHARACTERISTICS OF DAIRI BULLS

Correlation Between

No. of
Samples

Simple
Correlation
Coefficient (r)

Volume of semen and concentration of semen

2li70

-0.0856**

Volume of semen and percentage of sperms alive in non-stored semen

2bl0

-0.0531**

Volume of semen and progressive motility of sperm in non-stored
semen

2170

+o.okk2*

Concentration of semen and percentage of sperms alive in nonstored semen

2li70

+0.0629**

Concentration of semen and progressive motility of sperm in
non-stored semen

2li70

+0.0k30~

Percentage of sperms alive in non-stored semen and progressive
motility of sperm in non-stored semen

2i[70

+0.27kl**

Raw semen movement and volume of semen

120k

+o .0057

Raw semen movement and concentration of semen

120k

+0.kl95**

Raw semen movement and percentage of sperms alive in non-stored
semen

120k

+0 .2696

Raw semen movement and progressive motility of sperm in nonstored semen

120k

+0 .lk65**

" Significant at %

level of probability.

8ii

Volume of semen was positively correlated with progressive motility
of sperms in non-stored semen.
tically significant (5$ l e v e l ) .

The correlation was found to be statis­
A significant (5% level) positive corre­

lation was also noted between concentration of semen and progressive
motility of sperm in non-stored semen.

H o w e v e r , there was no significant

correlation between raw semen movement and volume of semen.
Table XVII shows simple correlation coefficients obtained for the
correlation of characteristics of dairy bull semen with percent of non- •
returns.

From the Table, it can be seen that there was liighly significant

(l % level) positive correlation between each of the following semen
characteristics and percent of non-returns.

However, the r-values (co­

efficient of correlation) obtained were small.
Progressive motility of sperms in non-stored semen
Raw semen movement
Concentration of sperms per 1/1000 cubic mm. of diluted semen
Percentage of sperms alive in U-day-old re-examined semen.
The correlation between volume of semen a.nd percent of non-returns
was not statistically significant.

Similarly, the correlation of the

concentration of semen and that of percentage of sperms alive in non-stored
semen, with percent of non-returns was not statistically significant.
The progressive motility of sperm either in 3-day-old or li-da.y-old re ­
examined semen was not significantly correlated with percent of non-returns.

TABLE XV'II
CORRELATION OF SSMEN CHARACTERISTICS OF DAIRY BULLS WITH PERCENT OF NON-RETURNS

Semen Characteristic

No. of
Samples

Simple
Correlation
Coefficient (r)

Volume of semen

1897

-tO .007k

Concentration of semen

1897

40.0138

Percentage of sperms alive in non-stored semen

1897

40.0100

Progressive motility of sperm in non-stored semen

1897

40.088k**

Raw semen movement

1000

40.1950**

Concentration of sperm per 1/1000 mm.3 of diluted semen

1887

40.1213

Progressive motility of sperm in 3-day-old re-examined semen

860

-0.0039

Percentage of sperms alive in k-day-old re-examined semen

O
CO

40.1262**

Progressive motility of sperm in k-day-old re-examined semen

630

40.okok

* Significant at 5% level of probability.
Significant at 1% level of probability.

86

(D)

discussion

Statistical analysis of the data, in the present investigation showed
a highly significant

level) negative correlation (r = -0.0856) between

volume of semen and concentration of semen of dairy bulls .
sults were reported by previous workers.

Contrary re­

Davis et, al. (1939) in dairy

bulls obtained a significant positive correlation (Pearson r = +0.3553)
whereas Lasley et a l . (191*3) in beef bulls found no significant correla­
tion of semen volume with concentration of semen.
In the present study, a highly significant (1 % level) negative corre­
lation (r = -0 .0531) was obtained between volume of semen and percentage
of sperms alive in non-stored semen.

The result obtained is not in agree­

ment with that reported by Lasley et al. (191*3) who found no significant
correlation in beef bulls .
Davis et a l . (1939) reported significant positive correlation between
sperm concentration and progressive motility of sperms (Pearson r = +0.3095)
in non-stored semen of dairy bulls.

Our results confirm the finding of

above investigators in that there wa.s a significant position correlation
between those characteristics.
In the present investigation, a. highly significant (l^ level) positive
correlation (r = + 0.27l*l) was noted between percentage of sperms alive
in non-stored semen and progressive motility of sperms in non-stored
semen.

Similar finding was also reported in beef bulls by Lasley (191*1*).

However, the correlation coefficient.reported b y Lasley was much
(r = +0.696) .

higher.

87

Lasley et al. (I 9 I4.3 ) in beef bulls reported highly significant cor­
relation between volume of semen and conception rate.

Mercier et a l .

(19ii6) in dairy bulls found no significant correlation between semen
volume and percent of non-returns.

The results obtained in the present

investigation are not in agreement with that reported by Lasley et a l .
(19U3) .

On the other hand, our results confirm the finding of Mercier

et a l . (1 9 U 6 ) in that there was no significant correlation between semen
volume end percent of non-returns.
Swanson et al.

(I9liii.) and Erb et al. (1950) found no significant

correlation between sperm concentration and conception rate or percent
of non-returns.

On the contrary, Mercier et al. (19U6)

and Branton et al

(1 9 5 1 ) noted highly significant ( 1 ^ level) correlation between sperm
concentration and percent of non-returns.

The results obtained in the

present study confirm the findings of Swanson et a l . ( 1 9 5 M

and Erb et al

(1 9 5 0 ) since no significant correlation was obtained in our study b e ­
tween concentration of semen ana percent of non-returns.
Erb et al . (1950) reported a high-ly significant (1% level) correla­
tion between percentage of sperms alive in non-stored semen and percent
of non-returns.

However, in the present investigation no significant

correlation was obtained between percentage of sperms alive in non-stored
semen and percent of non-returns.
Mercier et a l . (19L6) found no significant correlation between nuir.be
of sperm per insemination and the percent of non-returns.

On the other

hand, our results showed a highly significant (l>b level) correlation

88

between concentration of sperm per 1/1000 cubic mm. of diluted semen and
percent of non-returns.
The disagreements in the results reported by varioxis investigators
and also those obtained in the present investigation might be due to one
or more factors mentioned belowi
(1) Small number of samples
(2) Differences in methods used for determining various semen char­
acteristics
(3 ) Restriction as regards minimum requirements of various semen
characteristics (percentage of sperms alive, concentration of
semen, etc.) before semen sample could be sent for insemination
(U) Restriction regarding the total number of services from a semen
sample before it can be used in correlation study
(5) Type of animal (dairy or beef type)
In the present investigation, of all the semen characteristics under
study, the raw semen movement showed the highest correlation with percent
of non-returns.

Percentage of sperms alive in U-day-old re-examined

semen ranked 2nd to raw semen movement in correlation with percent of
non-returns.

Concentration of sperms per 1/1000 cubic mm. of diluted

semen ranked 3rd in correlation with percent of non-returns, whereas p r o ­
gressive motility of sperms in non-stored semen ranked irth in correlation
with percent of non-returns.

The results obtained suggest that in Michigan

Artificial Breeders Association, a semen sample meeting the minimum re­
quirements of semen characteristics or combination of semen characteristics
can possibly be judged with greaier accuracy as regards its potential

89

ability for higher percent of non-returns from the following character­
istics .

These characteristics are listed in order of importance.

Ra w semen movement
Percentage of sperms alive in U-day-old re-examined semen
Concentration of sperms per 1/1000 cubic mm. of diluted semen
Progressive motility of sperms in non-stored semen
The concentration of semen and the percentage of sperms alive in
non-stored semen m ay not be considered in judging the potential ability
for higher percent of non-returns, of a semen sample meeting the minimum
requirements of semen characteristics or combination of semen character­
istics in Michigan Artificial Breeders1 Association.

This is because,

in the present study there was no significant correlation between con­
centration of semen and percent of non-returns.

Similarly, the correla­

tion between percentage of sperms alive in non-stored semen and percent
of non-returns was not significant,
In the present investigation, there was no significant correlation
of progressive motility of sperms in 3-day-old. re-examined semen with
percent of non-returns.

Similarly, there was no significant correlation

of progressive motility of sperms in the l|-da.y-old re-examined semen with
percent of non-returns.

These results indicate that there is very little

to be gained by continuing observations on progressive motility of sperms
in 3— day and that in Ij.-day-old re-examined semen, so far a.s predicting
the percent of non-returns is concerned.
In the present study, a highly significant (l^ level) correlation
of raw semen movement and progressive motility of sperms in non-stored

90

semen was noted.
high.

However the correlation coefficient (r value) was not

Similarly, the correlation coefficient (r-value) for the correla­

tion of r a w semen movement and percent of non-returns was not high.

The

results suggest that the observations on progressive motility of sperms
in non-stored semen be continued even though the observations on raw semen
movement are being t a k e n .

(E )

SUMMARY AND C O N C L U S IO N S

The semen collection records of Micliigan Artificial Breeders Associ­
ation were studied from June 1, 1951 to May 31, 1952, lvith two objectives:
(l) to determine the inter-relationship of certain semen characteristics
and relationship between various semen characteristics and percent of
non-returns for dairy bulls, (2) to find the mean and distribution
(standard deviation) of certain semen characteristics of dairy bulls and
of beef b u l l s .
For the study of correlation of semen characteristics with percent
of non-returns, only the semen samples bred to UO or more females were
used.

The percentages of non-returns were based on 90-day non-returns of

females with 1, 2, 3, U , 5 and over current services.
The investigation led to the following findings and conclusions:Semen Characteristicst
(l)

Mean Values

Of all the dairy breeds under study, the semen volume was the

largest (7.2ml.)

in Guernsey and was the smallest (5.o ml.) in Jersey.

Concentration of semen was the highest (1869 per 1/1000 cubic mm.) in

91

Jersey and was the lowest (1727 per 1/1000 cubic mxn.) in Guernsey.
There was not m u c h difference between dairy breeds in the percentage of
sperms alive in non-stored semen and the progressive motility of sperms
in non-stored semen.
(2) The semen volume and concentration of semen were much greater
(1.5? mis. a.nd 174 per 1/1000 cubic mm., respectively)
than in Angus bulls.

in dairy bulls

The percentage of sperms alive in non-stored semen

and the progressive motility of sperms in non-stored semen were also
greater (2.1% and 0.9 %, respectively) in dairy bulls than the Angus bulls.
However, the raw semen movement in dairy bulls was somewhat low {0.6%) as
compared to that in beef bulls .
(3 ) The percentage of sperms alive in 4-day-old re-examined semen
and the progressive motility of sperms in 3-day and in 4-day-old re­
examined semen showed a marked decline as compared to fresh semen examined
soon after the collection.

Correlation between Semen Characteristics
(4) A highly significant {1% level) positive correlation between the
following pairs of semen characteristics was found.
Concentration of semen and percentage of sperms alive in non-stored
semen (r = +0.0829).
Percentage of sperms, alive in non-stored semen and progressive m o t i l ­
ity of sperms in non-stored semen (r = +0.2741).
R a w semen movement and concentration of semen (r = +0.4l?5>) .
Ra.w semen movement and percentage of sperms alive in non-stored
semen (r = +0.2698) .

92

R a w semen movement, and progressive motility of sperms in non-stored
semen (r = +0.1H65) .
There was a highly significant (1% level) negative correlation be ­
tween volume of semen and concentration of semen (r = -0 .0 8 5 6 ) and between
volume of semen and percentage of sperms alive in non-stored semen
(r = -0 .0531) .
Volume of semen was significantly correla.ted with progressive motility
of sperms in non-stored semen (r = +0.0UU2) .

A significant (5 % level)

positive correlation was also noted between concentration of semen and
progressive m otility of sperms in non-stored semen (r = +0.0li3).

However,

no significant correlation was found between raw semen movement and
volume of semen.

Correlation Between Semen Characteristics and Percent of Non-Returns
Higlily significant {.1% level) positive correlation was noted

(5 )

between each of the following semen characteristics and percent of non­
returns .

However, the r-values (simple correlation coefficient) obtained

were small.

Progressive motil i t y of sperms in non-stored semen (r = +O.O 8 6 J4)

R a w semen movement (r = +0.1950)
Concentration of sperm per 1/1000 cubic mm. of diluted semen
(r = +0.1213)
Percentage of sperms alive in [(.-day-old re-examined semen
(r = +0 .1 2 6 2 )
The volume of semen, concentration of semen and the percentage of
sperms alive in non-stored semen, were not significantly correlated with

93

percent of non-returns.

Similarly, no significant correlation was noted

between the progressive motility of sperms either in 3-day-ola or in k-dayold re-examined semen and percent of non-returns.
(6)

The results (r-values) obtained suggest that a semen sample

meeting the minimum requirements of semen characteristics or combination
of semen characteristics at Michigan Artificial Breeders Association can
possibly be judged with greater accuracy as regards its potential ability
for higher percent of non-returns from the following characteristics
listed in order of importance:
R a w semen movement
Percentage of sperms alive in k-day-old re-examined semen
Concentration of sperms per 1/1000 cubic mm. of diluted semen
Progressive motility of sperms in non-stored semen
(.7) Observations on progressive motility of sperms either in 3-day
or in k-day-old re-examined semen seem to be of very little use in pr e ­
dicting the percent of non-returns.
(8) The correlation of r aw semen movement with progressive motility
of sperms in non-stored semen (r = +0.lk65>) and that of raw semen movement
with percent of non-returns (r = +O.195>0) was highly significant (1>£ level)
However, the r-values were not large.

This, together with the fact that

there was a highly significant correlation (1% level) between the pro­
gressive motility of sperm in non-stored semen and the percent of non­
returns (.r = +0.088U)

suggests the desirability of continuing the observa­

tions on progressive motility of sperms in non-stored semen even though
the observations on raw semen movement are oeing recorded.

9h

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Anim.
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., and R. B o g a r t .
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Fertility of Dairy Bulls Used in Artificial Insemination.
Cornell V e t . , 3 6 : 301-311 •

98

Mercier, E., and G. W. Salisbury.
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Seasonal Variations in Hours of Daylight Associated with
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19U7b

Fertility level in Artificial Breeding Associated with
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Jour.
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19^3
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19U5
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.9
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, • J . E d w a r d s , C . E . Terr i l l , and
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I 9I4.O

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. , and H. A. Lardy.
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J o u r . Dairy S c i ., 23:
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Phillips, R. W., B. Knapp, L. C. Heemstra, and 0. N. Eaton.
I 9J4.3
Seasonal Variation in the Semen of Bulls. A m . J o u r .
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Salisbury, G. W. Recent Research Developments in the Preservation and
1951
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191*e
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Seath, D. M
19U1

1953
Shaffer, H
19A9

and C. H. Staples.
Some Factors Influencing the Reproductive Efficiency of
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Jour. D a i r y S c i ., 25: 510.
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Louisiana

, and J. 0. /Imquist.
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Jour. Dairy S c i ., 32:
723.
’’Seen in abstract only."

Swanson, it. W . The Efficiency of Artificial Breeding with Bull Semen
1951
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1981;

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1951b

Storage of D a i r y Bul l Spermatozoa.
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*The Correlation between Some Characteristics of Dairy
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Jour. Dairy S c i .,
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1953
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T r i m b e r g e r , G. W.
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Insemina.tion a.t Various Intervals Before and Af'ter
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19^3

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Underbjerg, G„, H. P. D a v i s , and R. E. Spangler.
19U2
Effect of Diluters and Storage u p o n Fecun d i t y of Bovine
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1U9-15U .
Vaidya, , G. W . , and P. Bhattachsrya
191*5
Artificial Insemination and Its Bear i n g on the
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Indian F m g . , 6:
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Livestock

VanDemark, N. L., and A. N. Moeller.
1951
Speed of Spermatozoan Transport in Reproductive Tract
of Estrous Cow.
A m e r . Jour . P h y s i o l ., 165:
67U-679.
________ _______ ., and G. W. Salisbury.
1950
The Relation of the Post-partum Breeding Interval to
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White, G. C., R. E. Johnson,
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________
19L0

., H. K. Fuller, and G. W. Salisbury.
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