NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
ORIGINAL ARTICLES
FIELD APPLICATION OF ARTIFICIAL INSEMINATION
IN CATTLE—I*
BY P. BHATTACHARYA AND S. S. PRABHU, Animal Genetics Section, Indian Veterinary
Research Institute, Izatnagar
(Received for publication on 15 February 1951)
ONE
of the major obstacles in the way of rapid and all round, improvement of
cattle in this country is the paucity of superior bulls [Royal Commission Report
on Agriculture, 1928; Wright, 1937]. The bulls issued for field use fall broadly
under two main categories; (i) those from recognized government or privately
owned farms and (ii) those selected from certain breeding tracts. Although the
selection of breeding sires on the basis of their phenotypic characters and/or their
pedigree records, which in many cases are incomplete, is not a sound method, con-
sidering the performance of the average. Indian cattle, it will be possible to effect
a quick improvement in quality, if the total annual bull requirement can be met
from the above two sources. As it happens, however, the availability falls far short
of the actual requirement, resulting in. the indiscriminate use of scrub bulls for
'settling' the cow. Consequentially, though the annual expenditure by the various
State Governments and local Bodies on cattle improvement work is considerable,
the resultant benefit accruing to the cattle industry as a whole is comparatively
small. Indeed, so long as natural mating is continued to be practised, the present
state of affairs in the country is bound to continue. The key to the solution of the
problem affecting cattle improvement really lies in the wider use of artificial insemina-
tion.
In practical animal husbandry, artificial insemination was successfully employed
for the first time by Ivanow [1907] in Russia; and it has been extensively used since
as an accepted method of breeding in many advanced countries. The special advan-
tage, among others, of the technique is the opportunity it provides for the economic
utilisation of the available semen from superior sires.
First organized attempts to study the applicability of artificial insemination
in this country were initiated in 1942 at the Indian Veterinary Research Insitute,
Izatnagar, under a scheme sponsored by the Indian Council of Agricultural Research.
The scheme started functioning from November, 1942, and came to a close in the
year 1945. The work has been subsequently continued in the Animal Genetics
Section, Indian Veterinary Research Institute. During the tenure of the Council's
scheme, various aspects of artificial insemination, such as training of bulls, collection
of semen and its preservation, method of insemination, long distance transport, etc.,
were studied. The results have been reported to the scientific committees of the
Council from time to time [Bhattacharya, 1942-1945; Guha, Kohli and Bhatta-
charya, 1947].
The results clearly demonstrated that there was not much difficulty in introduc-
ing this method in practical animal husbandry in India. But before its extensive
* The work has been carried out under a scheme of research financed by the Government of
India from the 'Grow More Food' fund.
163
164 APPLICATION OF ARTIFICIAL INSEMINATION IN CATTLE [Vol. XXII, Part III,
use was taken up on a country-wide scale, it was, however, deemed essential to
perform a larger number of inseminations under representative field conditions
obtaining in the country. This was found necessary in view of the practical diffi-
culties met with in the field [Vaidya and Bhattacharya, 1945]. With this end in
view four regional centres under the control of the Animal Genetics Section, Indian
Veterinary Research Institute, Izatnagar were established at the following sta-
tions:
(1) Calcutta Centre at Bengal Veterinary College (started functioning from
November, 1945).
(2) Montgomery Centre at Sir Datar Singh's Farm (started functioning from
December, 1945).
(3) Patna Centre at Bihar Veterinary College (started functioning from
January, 1946).
(4) Bangalore Centre at Indian Dairy Research Institute (started functioning
from January, 1947).
The Calcutta Centre and to some extent the Bangalore centre also worked
under conditions obtaining in large cities; whereas the other two were, practically,
under rural or semi-rural environments. The work at the first two centres materially
suffered during the communal disturbances before and after the partition. The
Montgomery centre had to be closed down in August 1947, owing to partition of
India.
The results reported in this article cover the period starting from the opening
of the centres upto the end of 1946.
Bulls used and their training.
There were in all 26 bulls at the three centres (16 Bos indicus and 10 Bos bubalis).
The Bos indicus bulls belonged to the following breeds: Sahiwal, Hariana, Nagori,
Tharparker and Indo-European Cross-bred. The Bos bubalis bulls were of the Nili
and Murrah breeds. The bulls were of different ages when brought into the scheme
and with the exception of two, were previously used to hand service. No difficulty
was experienced in ultimately training them to serve in the artificial vagina. It
was observed, however, that older bulls took longer time for training. The three
Sahiwal bulls purchased from Delhi were slow at service and as such were found to be
unsuitable for artificial service.
Number of Collections
Full particulars of collections from the bulls stationed at the three centres
are given in Table I. The details include information on the number of collections
made, the average volume of semen obtained per collection from each bull, breed,
and species. Out of the 27 bulls, 10 gave less than 10 collections, 3 less than 20,
while the maximum number of collections constituting 87 per cent of the total number
came from the remaining 14 bulls. The largest number of collections (84) were
made from the Tharparker bull No. 57-2, stationed at the Patna Centre. Even
this number falls short by twenty of the number of possible collections from a normal
routine of two collections per week. Considering the number of bulls, the total of
September, 1952] P. BHATTACHARYA AND S. S. PRABHU 165
TABLE I
Showing details of collections at the 3 Artificial Insemination Centres
Name of centre
1
Montgomery
Patna
Calcutta
Serial
number of
Bull
2
1
2
3
4
5
6
8
9
10
11
12
13
14
15
16
17
Brand number
3
K 600
J77/2.8
M.12/1.2
M.24/2.8
M.P. 1
M.P. 2
P. A.
158—2
57—2
7—2
12231
B. 441
B. 439
R. Mult
x -Bred 2
x -Bred 1
Hiralal
Breed
4
Sahiwal
Nili
Tharparker
Murrah
Indo-European
x
-Breds
Do
Nagori
Total number of collections per
Bull
5
17
30
28
20
35
40
60
21
84
73
35
11
16
20
28
28
31
Breed
6
95
135
213
27
76
31
Species
7
95
135
213
27
107
. .
Average volume (c.c.) of semen collection per
Bull
8
2.71±0.11
3.94±0.23
4.16±0.19
3.68±0.18
2.43±0.12
2.23±0.12
2.49±0.11
3.07±0.29
2.90±1.05
3.23 ±1.25
3.65±0.21
3.62±0.29
3.42±0.22
2.41 ±0.16
2.44±0.22
2.35 ±0.13
2.84±0.11
Breed
9
3.72±0.11
2.41±0.06
3.10±0.07
3.54±0.18
2.41±0.16
2.44±0.22
2.35±0.13
2.84±0.11
Species
10
3.72±0.11
2.41±0.06
3.10±0.07
3.54±0.18
2.56±0.08
September, 1952]
P. BHATTACHARYA AND S. S. PRABHU
167
TABLE II
Showing month to month variation in average semen volume
Month
December
January
February
March
April
May
June
July
August
September
October
November
December
Centre
Montgomery
B. indicus
(Sahiwal)
3.3
2.3
2.5
2.6
3.4
4.5
4.3
5.1
4.4
3.4
5.5
3.6
3.0
B. bubalis
(Nili)
2.9
1.9
2.1
2.8
3.5
3.4
1.6
1.9
2.6
1.7
2.3
2.5
2.9
Patna
B. indicus
(Thar-
parker)
1.7
16
2.4
2.3
3.5
3.2
3.0
3.3
3.7
3.6
4.6
3.7
3.2
B. bubalis
(Murrah)
. .
. .
. .
. .
. .
. .
. .
2.5
3.9
4.0
3.7
3.5
3.7
Calcutta
B. indicus
X-bred I
(Nagori)
1.8
1.6
1.9.
2.0
2.8
3.0
2.4
2.9
1.7
1.9
3.0
3.5
2.1
. .
. .
. .
. .
2.4
2.6
2.8
3.7
3.4
2.8
2.9
3.3
3.0
X-bred II
1.8
2.1
1.2
2.0
2.6
2.1
1.8
2.1
3.3
2.4
2.6
2.8
3.2
Inseminations
The insemination was done by using an all glass syringe fitted with a long
ebonite nozzle and a Russian model vaginal speculum. This method was used at
all the centres in spite of the disadvantage and loss of time involved in disinfecting
the speculum and nozzle after each operation. This is a serious consideration where
very large number of animals are to be inseminated in a short time. However,
this method was adopted as the number of animals coming to the centres during
the year under report was never unwieldy and because of the special advantage
offered by the method. namely, the detection of disorders of the reproductive tract
like vaginitis, cervicitis, etc., and finding out whether the semen deposited inside
the cervix was later on expelled or not.
Complete details as to the number of inseminations performed from the different
bulls at the three centres, including details regarding the number of inseminations
per collection, are given in Table III. It will be seen from the table that on the
whole a larger number of cows than buffaloes have been inseminated. It is of
September, 1952] P. BHATTACHARYA AND S. S. PRABHU 169
TABLE III
Showing details of inseminations performed at the 3 Artificial Insemination Centres
Name of Centre
1
Montgomery
Patna
Calcutta
Serial
number
of Bull
2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Brand
number
3
K 600
J 77/2.8
M.12/1.2
M.24/2.8
H 161.17
M.
P.1
M. P. 2
M. P. 3
M. P. 4
P. A.
158—2
57—2
7—2
12231
B.
441
B. 439
B.1
B. Mult.
X -Bred No. 2
X-Bred No. 1
Hiralal
Breed
4
Sahiwal
Hissar
Nili
Tharparker
Murrah
Indo-European
X -Bred
Foreign
Nagori
Total number of insemination per
Bull
5
24(17)
163(30)
164(28)
114(20)
17(5)
69(35)
151(40)
28(2)
101(8)
385(60)
120(21)
384(84)
359(73)
98(35)
67(11)
88(16)
34(9)
86(20)
147(28)
141(28)
195(31)
Breed
6
465(95)
17(5)
734(145)
961(213)
189(36)
374(76)
195(31)
Species
7
482(100)
734(145)
961(213)
189(36)
569(107)
Average number of inseminations per collection per
Bull
8
1.41
5.43
5.86
5.70
3.40
1.97
3.78
14.00
12.63
6.42
5.71
4.57
4.90
2.80
6.09
5.50
3.78
4.30
5.25
5.04
6.29
Breed
9
4.89
3.40
5.06
4.51
5.25
4.92
6.29
Species
10
4.82
5.06
4.51
5.25
5.32
NOTE.—Figures in brackets are number of collections.
170 APPLICATION OF ARTIFICIAL INSEMINATION IN CATTLE [Vol. XXII, Part III,
average number of animals inseminated from an ejaculum was practically the same
as at the other two centres using diluted semen. The average figure for three
centres works out at about five animals per ejaculum. Even with the low rate
of dilution followed by the centres namely 1: 3, this figure could easily have been
trebled.
In Russia, the first country to explore and utilise extensively the immense
possibilities of artificial service, the number of animals inseminated at each centre,
after seven years of organised work,works out at 239 per centre [Badirjan, 1938;
Neumann, 1939]. In Denmark, where the work was started in 1936 and the progress
had been very rapid, the number of cows inseminated per bull in 1944 comes to 699
[Twinch, 1946]. In the United States artificial insemination bulls were serving
342,012 cows which works out at 526 cows per bull [Twinch, 1946]. In England,
the technique became popular only during the later years of World War II. Accord-
ing to the figures published by the British Ministry of Agriculture [1946], between
June, 1945, and June, 1946, on an average one bull was serving 142 cows. At the
three Government of India Centres, with eleven effective bulls, 2198 inseminations
in all were performed. Taking the service rate into consideration, which is 1.3
for all bulls, the number of cows per bull comes to 146. In view of the fact that it
being only the first year's effort and that considerable time was spent in equipping
the laboratories of the centres, training the bulls and in educating the conservative
farmers to accept the new technique, the figure is very encouraging.
TABLE IV
Month to month variation in the total number of inseminations
Month
December, 45
January, 46
February, 46
March, 46
April, 46
May, 46
June, 46
July, 46
August, 46
September, 46
October, 46
November, 46
December, 46
Cows
Montgomery
10
8
4
33
48
73
49
58
53
40
49
48
59
Patna
2
29
23
23
50
89
92
115
125
113
117
83
113
Calcutta
11
13
14
26
50
75
60
56
21
26
41
64
92
Buffaloes
Montgomery
34
39
13
31
36
23
20
34
60
117
161
159
134
Patna
. .
. .
. .
. .
. .
. .
. .
1
21
44
49
35
48
Calcutta
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
September, 1952] P. BHATTACHARYA AND S. S. PRABHU 171
The figures in Table IV indicate the seasonal 'trend' in the activity of the centres.
But as this is the first year's work, no attempt is being made to draw any conclusions
at present.
Conception Rate
The success of the artificial insemination can be measured through the resulting
conception rates. Rowson [1944] has described three ways of calculating conception
rates :
(i) By adding all inseminations irrespective of whether the animals became
pregnant or not, and dividing this number by the number of pregnant
animals.
(ii) By adding up all the inseminations of the pregnant cows and dividing
by the number of pregnant cows.
(iii) By calculating the percentage of conceptions resulting from the first,
second and third, and subsequent inseminations.
American and British workers generally estimate inseminations required per
conception on the basis of 'non-returns' i.e., on the number of animals not presented
for 'repeat' insemination on completion of 5th month after insemination. In this
country, however, it often happens that when a cow repeats heat after an insemina-
tion, she is taken to a private bull, even for a number of times, and is not brought
for artificial insemination on account of recalcitrant prejudice. At other times,
false information is given that she is pregnant from an insemination, so as to escape
any further attempts for being convinced to take recourse to artificial insemination.
It has therefore been thought best to use only the correctly checked actual calving
data for all the inseminations made, for calculating the success of artificial insemina-
tion technique in field practice. Table V shows the number of services required
per conception at the 3 artificial insemination centres. They were comparatively
high for the Calcutta centre. The average overall rate for Bos-bubalis bulls was
1.39 as compared to 1.36 for the Bos indicus bulls. The difference is negligible.
As the rate depends to a large extent on the individuality of the bulls and of the
cows mated to them, no attempt has been made to test the differences statistically.
However, among the Bos indicus bulls, the lowest rate was shown by Sahiwal bull
No. K600 at Montgomery, and the highest was that by the Indo-European cross-bred
bull No. 2 at Calcutta. Among the buffaloes, Murrah bull B439 at Patna had the
lowest, and the Nili bull MP3 at Montgomery had the highest service rate.
Anderson [1939], after a careful examination of literature on reported fertility
of bulls, concludes that when a single service or insemination was allowed during
one heat period, highly fertile bulls when used with normal, regularly breeding
cows, required about 1.5 to 2.0 services per conception and this should be regarded
as normal. With the exception of the Calcutta centre, the number of services per
conception at the other two centres are less than 1.5. As the animals inseminated
usually came from the surrounding villages, this high fertility requires elucidation.
The possible explanation might be found in the fact that the animals were brought
172 APPLICATION OF ARTIFICIAL INSEMINATION IN CATTLE [Vol. XXII, Part III,
TABLE V
Showing details of number of services required per conception at the 3 Artificial Insemination Centres
Name of centre
1
Montgomery
Patna
Calcutta
Serial
number of
Bull
2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Brand
number
3
K 600
J. 77/2.8
M. 12/1.2
M. 24/2.8
H 161.17
M. P. 1
M. P. 2
M. P. 3
M. P. 4
P. A.
158—2
57—2
7—2
12231
B. 441
B. 439
B. 1
R. Mult.
X -Bred No. 2
X -Bred No. 1
Hiralal
Breed
4
Sahiwal
Hissar
Nili
Tharparker
Murrah
Indo-European
X Breed
Nagori
Total number whose claving data are
Known
5
24
142
155
106
16
69
136
24
78
335
120
374
355
97
67
88
34
54
113
109
129
Unknown
6
0
21
9
8
1
0
15
4
23
50
0
10
4
1
0
0
0
32
34
32
66
Holding
7
21
102
117
79
13
51
100
16
59
227
92
284
280
81
50
69
24
36
62
67
83
Average service rate per conception per
Bull
8
1.14
1.39
1.32
1.34
1.23
1.35
1.36
1.50
1.32
1.48
1.30
1.32
1.27
1.20
1.34
1.28
1.42
1.50
1.82
1.63
1.55
Breed
9
1.34
1.23
1.42
1.28
1.32
1.67
1.55
Species
10
1.33
1.42
1.28
1.32
1.63
September, 1952] P. BHATTACHARYA AND S. S. PRABHU 175
TABLE VI.
Showing relationship between volume, age and, treatment of semen and fertility.
Species
1
Bos bubalis
Bos indicus
Volume
injected in
c.c.
2
0.5
1.0
0.5
1.0
Name of A.I.
Centre
3
Montgomery
Patna
Calcutta
Montgomery
Patna
Calcutta
Montgomery
Patna
Calcutta
Montgomery
Patna
Calcutta
1 hour
Neat
4
1.63
1.29
..
1.40
..
..
1.30
1.30
..
1.18
1.23
..
Diluted
5
1.47
..
..
..
..
..
1.14
1.26
..
..
1.30
1.66
Average Service rate per conception
Above 1, but less than
24 hours
Neat
6
..
1.36
..
2.20
..
..
1.42
1.38
..
..
1.25
..
Diluted
7
1.40
..
..
1.57
..
..
..
..
..
..
..
1.46
Above 24, but less than
48 hours
Neat
8
..
1.29
..
..
..
..
1.40
1.29
..
..
..
..
Diluted
9
1.28
..
..
1.23
..
..
..
..
..
..
..
2.59
Above 48, but less than
76 hours.
Neat
10
..
1.38
..
..
..
..
1.38
1.32
..
..
..
..
Diluted
11
..
..
..
1.32
..
..
..
..
..
1.23
..
2.16
176 APPLICATION OF ARTIFICIAL INSEMINATION IN CATTLE [Vol. XXII, Part III,
SUMMARY
Results of 2,935 inseminations made from 601 ejaculates collected from thirteen
Bos indicus and eight Bos bubalis bulls stationed at the Montgomery, Patna, and
Calcutta field artificial insemination centres run by the Animal Genetics Section
of the Indian Veterinary Research Institute are analysed and discussed.
ACKNOWLEDGEMENTS
The authors wish to thank Mr. D. B. Mukherjee, Ch. Chetram, and Sardar
Gajjan Singh, the Officers in-Charge of the Calcutta, Patna, and Montgomery artificial
insemination centres respectively, for much help in introducing artificial insemination
in the field. The basic data collected by them have been used in the preparation
of this article. Thanks are also due to the Civil Veterinary Departments of Bengal,
Bihar, and Punjab for their wholehearted co-operation; to Sir Datar Singh, Vice-
President, Indian Council of Agricultural Research, to Mr. S. K. Sen, Director of
Animal Husbandry Department, Bihar, and to Major J. M. Lahiri, Principal of
Veterinary College, Bengal, for their personal interest and for providing full facilities
in conducting the work ; to Major Williamson for the help, advice, and co-operation
ungrudgingly given by him in setting up the artificial insemination centres, and
to the Director of the Indian Veterinary Research Institute, Izatnagar, for help
and advice at all stages during the progress of the work.
REFERENCES
Anderson, J. (1939). Investigations on the Semen of Fertile and Sterile Bulls. Vet. J., 95, 457-473;
96, 18-27
——(1945).
The Semen of Animals and its use for Artificial Insemination. Imp. Bur. An.
Genetics, Edinburgh
Andreev, E. L. (1937). Insemination of Cows twice during one Heat period. Probl. Zivotn.,
No. 5, 134-138
Badirjan, G. (1938). (Efficiency and some problems of organisation of Artificial Insemination
of cattle and sheep.) Socialist. Rekonstr. Selisk. Hoz. No. 3, 193-202 (Abstract in A.B.A.,
9, 4, 1941)
Ayyer Vermani (1944). Indian Vet. J., XX, No. 5 : 253. (Citation from Shukla and Bhatta-
charya (1949).)
Bartlett, S. and Perry, E. J. (1939). Lesson learned from 18 months experience with Co-operative
Artificial Breeding of Dairy cattle in New Jersey. Proc. Amer. Soc. Anim. Prod. 32nd
Meet., 243
Bartlett, S. (1944). The Reading Centre for the Artificial Insemination of Dairy cattle. Agric.
Progr. 19, 25-27
Bhattacharya, P. (1942-1945). Artificial Insemination Scheme. Progress reports submitted
to Indian Council of Agricultural Research, Delhi
Brewstar, J. E., May, R., and Cole, C. L. (1940). The Time of Ovulation and Rate of Sper-
matozoa Travel in Cattle. Proc. Amer. Soc. Anim, Prod. 33rd Meet. 304-311
Burch, G. E. (1939). Artificial Insemination in New York State Dairy Herds. Vet. Rec., 29,
395-406
Davies, H. P. and Williams, N. K. (1939). Evaluating Bovine Semen I. Influence of the
number of Ejaculates upon various Physical and Chemical Characteristics and the Rela-
tionship between those factors. Proc. Amer. Soc. Anim. Prod. 32nd Meet., 232-245
178 APPLICATION OF ARTIFICIAL INSEMINATION IN CATTLE [Vol. XXII, Part III,
Smirnov-Ugrjumov, D. V. (1945). Experience in the Organisation of an Artificial Insemination
Centre serving several Collective Farms. Trud. Lab. iskusst. Odemen. Zivotn. (Mosk.),
2, 43-48. (Abstract in A. B. A.)
Synder, W. E. and Baltzer, A. C. (1945). Preliminary Results of Artificial Insemination through
a Co-operative enterprise. Quart. Bull. Mich. Agric. Exp. Sta., 27, 310-312
Trimberger, G. W. and Davies, H. P. (1943). Res. Bull. Neb. Agric. Exp. Sta. No. 129 (Citation
from Laing, 1945 a)
Twinch, H. (1946). Progress in the Application of Artificial Insemination in other countries.
Proc. Brit. Soc. Anim. Prod. V meet., 51-58
Underjberg, Davis, H. P., and Spangler, R. E. (1942). Effect of dilutors and Storage upon
Fecundity of Bovine Semen. J. Anim. Sci., 1, 149-155
Vaidya, G. W. and Bhattacharya, P. (1945). Artificial Insemination and its bearing on the
Livestock Industry of India. Indian Fmg., 6, 561-565
Vighenzie, D. (1946). 5 years of Artificial Insemination at the Rorre de' Picenadi Centre.
Zootec. e Vet., 1, 104-109 (English Summary) (Abstract in A. B. A., 15, 178, 1947)
Wialton, Arthur (1933). The technique of Artificial Insemination. Imp. Bur. An. Genetics,
Edinburgh
Willett, E. L., Fuller, H. K., and Salisbury, G. W. (1940). Preservation of Bovine Spermatozoa
in Yolk Phosphate Diluent and Field Results from its use. Cornell Vet., 30, 507-513
Wright, N. C. (1937). Report on the Development of the Cattle and Dairy Industries of India.
Published by Manager of Government of India Publications, New Delhi
SEASONAL VARIATION IN 'REACTION-TIME' AND SEMEN
QUALITY OF GOATS
By D. D. SHUKLA AND P. BHATTACHARYA,
Animal Genetics Section, Indian Veterinary Research Institute, Izatnagar
(Received for publication on 16 January 1952)
(With one text-figure)
IN recent years several investigations have been carried out into the influence
of seasons on the semen quality of farm animals. It has been found by Mukherjee
and Bhattacharya [1947] and Shukla and Bhattacharya [1947] working with Indian
bulls and rams respectively that the semen qualities of the animals vary in different
seasons. They have found that high air temperature associated with high relative
humidity and rainfall as found in autumn (i.e., from August to October) has an adverse
effect on semen quality of these two species of farm animals. Little information is
available regarding the seasonal influence on semen quality of goats. Phillips et al.,
[1943] studied the seasonal variation in bucks of Saanen and Toggenburg breeds at
Maryland (U. S. A.). Their observations were, however, limited to only two bucks,
one of each breed. In view of the scanty information available in respect of the
indigenous goat, it was considered desirable to study the effect of different seasons
on its semen quality.
MATERIAL AND METHODS.
Experimental animals consisted of eight goats purchased from the local market
They were all mature bucks between two to three years of age at the commencement
of the experiment. Before the commencement of the experiment they were trained
to mount an anoestrous doe and ejaculate semen in artificial vagina. Throughout
the experimental period the animals were kept under the same managerial and dietary
conditions as reported for rams by Shukla and Bhattacharya [1947]. Two
collections of semen at an interval of 15 minutes were made from each animal every
fortnight for two consecutive years, and under the same climatological conditions
under which Mukherjee and Bhattacharya [1947] and Shukla and Bhattacharya
[1947] respectively observed seasonal variations in the semen quality of bulls and
rams. Each semen sample was examined for the following characteristics :
(1) Colour and consistency.
(2) Volume of semen.
(3) Initial motility of spermatozoa.
(4) pH of semen.
(5) Sperm concentration per ml. of semen.
(6) Total number of spermatozoa and
(7) Percentage of abnormal spermatozoa.
179