NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
GENETIC CAUSES OF VARIATION IN THE LENGTH OF
GESTATION OF BUFFALOES
By Y. S. GHANEM1, A. ZAHER2, A. ABUL-FADL and F. A. SOLIMAN,
Departments of Zoology and Physiology, Faculty of Veterinary Medicine, Cairo
University
(Received for publication on 16th December 1954 )
T HE fact that the length of gestation is a species characteristic [Lush, 1945],
seems to suggest that it might be due to direct genetic influence. Variations in
gestation length also exist within species, and are attributed partly to differences
in the genetic make-up of the individuals belonging to the same species, and partly
to certain environmental factors such as season and year of service or parturition
age of dam, etc. Significant differences in gestation length between breeds of
cattle were observed by Rife et al., [1943] and Livesay and Bee [1945]. It has been
suggested that these inter-breed differences are hereditary [Shrode and Lush, 1947].
Other evidences of the effect of heredity on pregnancy duration have been provided
by several studies of correlations between relatives. Significant differences in the
gestation lengths of calves sired by different bulls were reported by Rife et al. [1943],
Bonadonna and Valerani [1946], Alexander [1950], and Jafar et al., [1950]. Similar
results were obtained by Ragab and Asker [1951] in the buffalo. The effect of the
dam on gestation length has also been found significant in cattle [Knapp et al., 1940 ;
Jafar et al., 1950] and in buffaloes [Ragab and Asker, 1951]. The components of
variance in pregnancy duration were estimated by Jafar et al., [1950] and they con-
cluded that the genotype of the calf was responsible for 48 per cent of the total
variance.
MATERIAL
The lengths of 424 gestations of 126 buffaloes out of 15 sires, covering the period
from 1935 to 1951 were used in this study. They were obtained from the breeding
records of Bahteem farm of the Egyptian Agricultural Society and were described
by Ghanem et al., [1954].
ANALYSIS AND RESULTS
The data were adjusted for sex of calf and season of calving according to the
results previously obtained by Ghanem et al., [1955]. Statistical analysis was then
carried out, using the analysis of variance method described by Snedecor [1946].
Paternal half sibs
The progeny of ten sires that had the largest number of offspring were used
to study the differences between paternal half sibs. These differences were found
to be highly significant [Table I]. The intraclass correlation between paternal half
sibs was 0.0571 ± 0.05.
1 Present address : Zoology Dept., Faculty of Science, Cairo University
2 Present address : Animal Production Dept., Faculty of Agriculture, Heliopolis University
307
36 AR/55
9
308
LENGTH OF GESTATION IN BUFFALOES
[ Vol. XXV, Part IV,
TABLE I
Analysis and components of variance of gestation length in families of paternal
half sibs
Source of variation
Between sib families
Within sib families
Degrees
of
freedom
9
404
Mean
square
187.5**
56.9
Expected value
of mean square
37.9σp 2 +σ 2
σ 2
Variance
component
3.4
56.9
Percent
of total
variance
5.7
94.3
** P<0.01
Maternal half sibs
The gestation lengths obtained from 110 dams having more than one offspring
were analysed [Table II]. The differences between maternal half sibs were found
to be highly significant, and the intraclass correlation was 0.3018 ± 0.05.
TABLE II
Analysis and components of variance of gestation length in families of maternal
half sibs
Source of variation
Between sib families
Within sib families
Degrees
of
freedom
109
293
Mean
square
92.1**
40.0
Expected value
of mean
square
3.0 1 σ 2 t+σ 2
σ 2
Variance
component
17.3
40.0
Percent of
total
variance
30.2
69.8
** P<0.01
Full sibs
A study of 76 full sib families revealed that they differed significantly among
themselves [Table III]. The intraclass correlation between full sibs was found to
be 0.4086 ± 0.08.
TABLE III
Analysis and components of variance of gestation length in full-sib families
Source of variation
Between sib families
Within sib families
Degrees
of
freedom
75
93
Mean
square
80.0**
32.2
Expected value
of mean square
2.2 1σf 2 σf 2 +σ 2
σ 2
Variance
component
22.2
32.2
Per cent
total
variance
40.9
59.1
** P<0.01
December, 1955 ] Y. S. GHANEM, A. ZAHER, A. A. FADL AND P. A. SOLIMAN 309
Components of variance
The correlation between paternal half sibs contains one-fourth of the variance
due to additive genes and about one-sixteenth of the epistatic deviation from the
additive scheme [Wright, 1935; Lush, 1945]. These components are also included
in the maternal half-sib correlation together with the variance caused by common
maternal environment. Thus, simply subtracting the paternal half sib correlation
from that of the maternal half-sibs gives an estimate of the variance caused by per-
manent maternal traits. The correlation between full sibs is an estimate of half of
the variance due to additive genes, one-quarter of the dominance deviations, about
one-quarter of the epistatic deviations and the variance due to permanent
maternal characteristics.
Three simultaneous equations were obtained by using the above definitions
and were then solved [Table IV]. The variance due to permanent maternal traits
TABLE IV
Correlations among different sets of sibs and estimates of their theoretical components
Relationship
Paternal half sibs
Maternal half sibs
Pull sibs
Number
413
402
168
Intraclass
correlation
0.0571±0.05
0.3018±0.05
0.4086±0.08
Estimated components
¼7σg 2 +1/16 σi 2
¼σ g
2 +1/16σ t
2 +σ m
2
½σ g
2 +¼σ d
2 +¼σ i
2 +σ m
2
Variance due to additive genes
„
„ „ epistatic deviations
„
„ „ dominance deviations
„
„ „ permanent maternal traits
σ g
2 =0.312
σ i
2 =0.000
σ d
2 =0.031
σ m
2
=0.245
σ m
2 was found to be 0.245. The portion of variance due to epistatic deviation
σ i
2 was assumed negligible and was given the value zero [Lush, 1948]. The variance
due to additive genes was obtained by using the formula σ g
2 = p/x, P being the
intraclass correlation for paternal half sibs, and r the genetic relationship between
half sibs. In a random breeding population r = 0.25 for half sibs ; but as there was
some relationship between the sires, r becomes equal to r 1 r 2 /1-r 1 [Lush, 1945],
r 1 being 0.25 and r 2 , the average relationship between sib families, being 0.113.
The variance due to additive genes was thus found to be 0.312. The variance due
310
LENGTH OF GESTATION IN BUFFALOES
[ Vol. XXV, Part IV,
to dominance deviation σ d
2 was found to be 0.031. The percentages of the different
components of variance are presented in Table V. They include those components
due to season of calving, sex of calf and age of dam [Ghanem et al., 1955].
TABLE V
Components of variance of gestation length
Source of variation
Genotype of calf-
Additive genes
Dominance deviations
Epistatic deviations (arbitrary)
Permanent maternal traits
Season of calving
Sex of calf
Age of dam
Residual
TOTAL
Variance
per cent
31.2
3.1
0.0
24.5
4.1
2.2
8.0
26.9
100.0
DISCUSSION
The progeny of different sires were found to differ significantly among them
selves. This agrees with the findings of Rife et al., [1943], Bonadonna and Valerani
[1946], Alexander [1950], Jafar et al., [1950], and Ragab and Asker [1951]. The
differences among sire families indicate genetic influence on the length of gestation
of the buffalo. This fact was further verified by the detection of highly significant
differences among different sets of maternal half sibs, and also among full sib families.
The estimate obtained for the portion of variance due to additive genes was
31.2 per cent, which is close to the 32 per cent obtained by Jafar et al., [1950] in cattle.
Also, the estimate of permanent meternal traits obtained by the latter authors in
cattle [21 per cent] is close to the 24.5 per cent estimated in the present study.
Thus in buffaloes, more than 50 per cent of the total variance in gestation length
may be attributed to heredity.
Although the above estimates are only approximate (the epistatic deviations
were assigned the arbitrary value of zero), yet it is safe to conclude that gestation
length in buffaloes is a highly heritable character. Accordingly, serious considera
tion could be given to this character during selection. It may be possible, by using
the proper systems of breeding and selection, to decrease the average length of
gestation in the buffalo. This will shorten its calving interval, and could thus help
to increase its total life-time production.
December, 1955] Y. S. GHANEM, A. ZAHER, A. A. FADL AND F. A. SOLIMAN 311
SUMMARY
The records of 424 gestations were used to study the genetic causes of variation
in gestation length of the Egyptian buffalo. The partitioning of the total variance
yielded 31.2, 3.1 and 24.5 per cent for the additive genetic variance and the variance
due to dominant deviations and permanent maternal traits respectively.
REFERENCES
Alexander, M. H. (1950). Length of Gestation in the Five Major Breeds of Dairy Cattle, Abstr.
J. Dairy Sci., 33 : 377
Bonadonna, T. and Valerani, L. (1946). Investigations and Observations on the Fertility of Several
Lombardy Herds. Zootech. e Vet., 1: 129-150 and 274-287. (Anim, Breed. Abstr., 15 : 174,
1947)
Ghanem, Y. S., Abdul Fadl, A., Zaher, A. and Soliman, F. A. (1955). Environmental Causes of
Variation in the Length of Gestation of Buffaloes (in the present issue)
Jafar, S. M., Chapman, A. B. and Casida, L. E. (1950). Causes of Variation in Length of Gestation
in Dairy Cattle. J. Anim. Sci., 9: 593-599
Knapp, Jr. B., Lambert, W. V. and Black, W. H. (1940). Factors Influencing Length of Gestation
and Birth Weight in Cattle. J. Agric. Res., 61 : 277-285
Livesay, E. A. and Bee, U. G. (1945). A Study of the Gestation Periods of Five Breeds. J. Anim.
Sci., 4 : 13-14
Lush, J. L. (1945). Animal Breeding Plans, Third Edition, Iowa State College Press, Ames, Iowa.
——(1948).
The Genetics of Populations, Memeographed, Ames, Iowa.
Ragab, M. T. and Asker, A. A. (1951). Factors Influencing Length of Gestation Period in Egyptian
Cattle and Buffaloes. Indian J. Dairy Sci., 4 : 159-169
Rife, D. C., Gerlaugh, P., Kunkle, L., Brandt, G. and Snyder, L. (1943). Comparative Lengths of
Gestation Periods of Abardeen-Angus and Hereford Cows Carrying Purebred and Crossbred
Calves. J. Anim. Sci., 2 : 50-52
Shrode, R. R. and Lush, J. L. (1947). The Genetics of Cattle—Advances in Genetics, Vol. I, Aca-
demic Press Inc., N. Y.
Snedecor, G. W. (1946). Statistical Methods, fourth edition, Iowa State CollegePress, Ames, Iowa.
Wright, S. (1935). The Analysis of Variance and the Correlation between Relatives with Respect to
Deviations from an Optimum. J. Genet. 30: 243-251
36 AR/55
10
PHYLOGENETIC SIGNIFICANCE OF SPINA BIFIDA IN
ZEBU CATTLE
By H. EPSTEIN, Lecturer in Animal Breeding, Faculty of Agriculture, Hebrew
University, Jerusalem
( Received for publication on 12th August 1954.)
( With Plates VII-VIII )
H UMPED cattle may be grouped into two main divisions : the flesh-humped
and the fat-humped. In flesh-humped cattle the hump is cervico-thoracic in
situation and muscular in structure, while in fat-humped animals the situation of
the hump is thoracic and the structure musculo-fatty [Curson and Bisschop, 1935].
Flesh-humped cattle include two groups : the flesh-humped zebu and the
flesh-humped sanga. The flesh-humped zebu is recorded from ancient Egypt and
Elam. But only one flesh-humped zebu breed has survived, i.e. the Afrikander
cattle of South Africa, which have descended from the cattle of the Hottentots [Eps-
tein, 1933]. The flesh-humped sanga cattle, found in Abyssinia and the savanna
belts of Africa, originate from the interbreeding of flesh-humped zebu and straight-
backed longhorn cattle.
Fat-humped cattle also comprise two groups : the fat-humped zebu and the fat-
humped sanga. The fat-humped zebu ranges practically throughout the whole of
southern Asia. During recent centuries it has been introduced into East Africa
by Arab and Indian traders, from whence it has rapidly extended its range south-
wards and westwards owing to its superiority to the flesh-humped sanga cattle
in hardiness and production. Fat-humped sanga breeds are found in Madagascar
and throughout those parts of Africa where fat-humped zebus have interbred with
flesh-humped sangas or humpless longhorn cattle.
Humped cattle are occasionally encountered also among breeds which do not
include a zebu strain. The feral park cattle of Chillingham, for instance, which
have no connection with the zebu group, occasionally develop humps [Owen, 1856].
A cervico-thoracic hump occurs also in some of the brachyceros cattle of Egypt
and western Asia, although there are no flesh-humped zebu cattle among their
ancestors.
In addition to the hump and some other less significant conformational
characteristics, the zebu group as a whole, irrespective of the situation and
structure of the hump, is distinguished by the shape and direction of the spinous
processes of the dorsal vertebrae. From the seventh vertebra on the spinous pro-
cesses are bifid, whereas in humpless cattle of both the longhorn (primigenous)
and shorthorn (brachyceros) basic types they are generally single [Curson and
Epstein, 1934].
313
36 AR/55
11
PLATE VII]
[Indian J. vet. Sci. Vol. XXV, Part IV,
FIG. 1. Ninth dorsal vertebra of flesh-
humped zebu (Afrikander) cow. After
Curson and Epstein.
FIG. 2. Ninth dorsal vertebra of fat-humped zebu (Bengal) Bull and Cow.
After Curson.
36 AR/55.
PLATE VIII]
[Indian J. vet. Sci. Vol. XXV, Part IV,
FIG. 3. Ninth dorsal vertebra of brachyeeros
(West Africa) bull. After Curson and
Epstein.
Fig. 4. Ninth
dorsal vertebra of flesh-
humped sanga (Ovambo) cow and
(Zulu) ox. Oondersteport collection
Fig. 5. Ninth dorsal vertebra
of
fat-humped sanga
(Madagascar) cow. Oonder-
stepoort collection.
Fig. 6. Different developmental types of the processus
spinosi in mammals. After Mijsberg.
316
PHYLOGENETIC SIGNIFICANCE IN ZEBU CATTLE [ Vol. XXV, Part IV,
hyperapophyses, forming the main portion of the spinous process, remain terminally
separate. This would indicate a genetical basis of spina bifida, such as Hammond
[1940] postulates for this character in the rabbit. While opposing the hypothesis
that mechanic agency due to increased muscular development may be responsible
for the evolution of spina bifida, Mijsberg does not deny the possibility that reduced
mechanic requirement may be a contributory factor "as it is very probable that
the bifurcated processes are to be regarded as less strong than those in which the
halves are completely joined."
However, there is no proof that reduced mechanic pressure has any greater
significance in the formation of spina bifida than has increased mechanic requirement.
From its rather erratic occurrence in other animals, including man, in the most
various parts of the spine, it would appear that spina bifida in zebu cattle has
neither positive nor negative selective value. It is doubtless genetically linked to
the hump factor ; but the exceptions indicate that the linkage is not complete.
The mode of inheritance of spina bifida in the cross-breeding of zebu and straight-
backed cattle is still unanalysed. Along with the hump, which like the fat tail
and fat rump in sheep has been evolved under domestication, spina bifida in the
neural spines of the anterior dorsal vertebrae of zebu cattle appears to be a domes-
tication feature, offering no clue in the quest of the wild ancestors of the zebu.
REFERENCES
Curson, H. H. and Bisschop, J.H.R. (1935). Some Comments on the Hump of African Cattle.
Anatomical Study No. 60. Onderstepoort J. Vet. Sci. 5. 2
———and
Epstein, H. (1934). A Comparison of Hamitic Longhorn, West African Shorthorn
and Afrikander Cattle particularly with regard to the Skull. Anatomical Study No. 50 On-
derstepoort J. vet. Sci. 3, 2
Duorst, J. U. (1931). "Grundlagn der Rinderzucht"—Berlin
Epstein, H. (1933). Descent and Origin of the Afrikander Cattle. J. Heredity. XXIV, 12
Gans, H. (1915). Banteng and Zebu und ihr gegenseitiges Verhaelinis. Kuchns Archiv. VI, Halle
Hammond, J. (1940). Farm Animals.—London.
Klatt, B. (1927). Entstchung der Haustiere. Handbuch der Vererbungswissenschaft III, Berlin
Mijsberg, W. A. (1926). "Die Morphogenie der Wirbeldornen der Sacuger, im besonderen des Menschen"'
Zeitschr. f.d. ges. Anatomie. I. 79
Owen, R. (1856). On the Ruminant Quadrupeds and the Aboriginal Cattle of Great Britain. Notices
of Proceedings of the Meetings of Members of the Royal Institution of Great Britain. 2.
Pettit, A. (1909). Sur la Bosse du Zebu de Madagascar (Bos Indicus L.). Annales des Sciences Naturelles
Ser. 9 Zool. IX Paris
Von Eggeling, H. (1922a). Die Halswirbeldornen und deren Muskeln bei Halbaffen.
Anatomischer
Anzeiger, 55
———(1922b).
Die Gabelung der Halswirbeldornen und ihre Ursachen. Anatomischer Anzeige r
55
SEASONAL VARIATIONS IN REACTION TIME AND SEMEN
QUALITIES OF BUFFALO-BULLS
By N. S. KUSHWAHA, D. P. MUKHERJEE and P.P.BHATTACHARYA, Division of Animal
Genetics, Indian Veterinary Research Institute, Izatnagar
(Received for publication on 14th January 1955)
(With two text-figures)
A LTHOUGH in farm animals spermatogenic activity goes on continuously
after the attainment of puberty and they are capable of mating throughout
the year, there are evidences in the literature to show that their semen quality and
quantity vary in different geographical regions as well as during different seasons
of the year. Seasonal variation in semen qualities under Indian climatic conditions
have been studied in the case of bulls by Mukherjee and Bhattacharya [1952] while
in the case of sheep and goats by Shukla and Bhattacharya [1952 a and b]. As
buffalo is an important species of farm animals and is entirely different from the
other species of experimental animals studied by previous workers, it was considered
worthwhile to study the seasonal variation, if any, in the semen qualities of buffalo.
MATERIAL AND METHODS
The experimental animals comprised six Murrah buffalo bulls. All the bulls
were of four to six years of age at the commencement of the experiment. During
the entire experimental period of two years the bulls were kept under uniform mana-
gerial and dietary regime. The ration supplied to each bull consisted of a concentrate
mixture containing linseed cake 50 parts, wheat bran 30 parts, crushed oats 10
parts and crushed maize 10 parts. All the animals, excepting one bull, No. 22
which due to lighter body weight received 4 lb. of the mixture, received 5 lb. of the
mixture and 2 oz. of common salt per day. Beside the mixture, each animal received
6 lb. of dry roughage and 30 lb. of green fodder. They were also allowed free grazing
for four to five hours a day. During the pre-experimental period, the animals were
trained to mount an anoestrous buffalo-cow confined in a service crate and to ejaculate
seamen in the artificial vagina.
In order to estimate the monthly variations in semen quality and quantity of
the individual bull weekly collections of a semen sample from each animal were made
throughout the experimental period of two consecutive years. The semen character-
istics studied were, (i) volume, (ii) initial pH, (iii) initial motility of spermatozoa
(iv) sperm concentration per unit volume of semen, (v) total number of spermatozoa
per ejaculate and (vi) percentage of abnormal spermatozoa. Each sample was
examined for its volume, pH and initial motility was made immediately after collec-
tion. Volume was measured to the nearest 1/10 ml. The degree of motility was
scored in terms of criteria as recommended by Erb et al., [1942]. Hydrogen-ion
concentration and percentage of abnormal spermatozoa were determined accor-
ding to the methods described by Mukherjee and Bhattacharya [1952].
317
36 AR/55
12
December, 1955 ] N. S. KUSHWAHA, D. P. MUKHERJEE AND P. BHATTACHARYA 319
TABLE I
Monthly average of reaction time, semen characteristics, air temperature and relative humidity during the
experimental period
Factors
Reaction time in seconds
Volume of semen in ml.
Initial motility of spermatozoa
Initial pH of semen
Sperm concentration millions/ml.
Total number of spermatozoa millions/ejaculate
Percentage of abnormal spermatozoa
Minimum air temperature Oº F
Maximum air temperature Oº F
Relative humidity per cent
Reaction time in seconds
Volume of semen in ml.
Initial motility of sepermatozoa
Initial pH of semen
Sperm concentration millions/ml.
Total number of spermatozoa millions/ejaculate
Percentage of abnormal spermatozoa
Minimum air temperature Oº F
Maximum air temperature Oº F
Relative humidity per cent
January
40.0
1.9
3.5
6.8
899.2
1744.0
7.6
48.6
72.6
76.6
49.2
3.1
3.6
6.7
837.9
2646.4
9.7
46.2
68.9
77.9
February
47.0
2.1
3.6
6.7
1012.9
2039.2
5.5
48.9
73.6
62.5
51.6
2.2
3.9
6.9
874.9
1775.6
10.7
51.0
76.3
65.1
March
74.0
2.2
4.3
6.6
1056.0
2308.4
4.1
57.6
83.5
50.1
77.6
2.6
4.5
6.7
894.4
1985.7
4.1
59.0
87.9
50.9
April
44.0
2.3
4.5
6.7
1187.5
2656.9
2.7
67.7
89.3
32.0
59.5
2.4
4.2
6.5
929.3
2120.6
8.2
67.7
94.5
41.5
May
50.6
2.3
3.7
6.7
1162.3
2798.2
5.6
77.6
105.4
38.1
63.1
2.5
3.9
6.7
1003.0
2614.8
8.2
79.6
104.4
44.2
June
July
1949-50
52.2
2.6
3.2
6.8
875.4
2571.5
7.1
79.6
100.3
61.3
53.6
2.6
3.5
6.8
927.7
2389.3
7.4
79.3
90.4
82.4
1950-51
45.9
2.8
4.1
6.7
1234.6
3362.8
8.9
85.6
105.2
55.7
53.6
3.3
4.3
6.6
1003.1
2907.8
7.2
80.1
99.2
69.4
August
37.1
2.3
3.1
6.7
1019.8
2238.1
14.4
79.3
89.2
88.2
43.3
3.0
3.6
6.6
1036.3
3096.6
7.2
78.9
89.6
86.0
Septem-
ber
32.5
1.7
3.5
6.7
790.7
1307.1
6.8
77.7
88.8
82.6
58.4
2.9
3.2
6.8
1004.6
2700.0
6.6
75.0
89.1
79.2
October
28.3
1.8
3.4
6.9
802.5
1511.8
4.8
68.2
86.3
67.3
54.8
2.4
3.3
6.8
839.9
1910.1
5.9
62.1
88.2
67.4
Novem-
ber
42.0
2.1
3.4
6.8
777.0
1735.9
5.1
50.4
79.4
67.3
57.0
2.5
3.1
6.9
861.0
1948.1
6.8
51.2
82.1
64.4
Decem-
ber
42.9
2.3
3.5
6.7
752.9
1653.8
8.5
44.3
77.0
60.9
59.7
2.6
3.3
6.8
957.5
2612.9
10.0
45.7
72.7
69.1
320
SEMEN QUALITIES OF BUFFALO-BULLS [Vol. XXV, Part IV,
TABLE II
Summary of the analysis of variance of semen characteristics and meteorological data
Factors analysed
Reaction time
Volume of semen
Initial motility of spermatozoa
pH of semen
Sperm concentration
Total number of spermatozoa ejaculate
Percentage of abnormal spermatozoa
Average temperature
Average humidity
Between
bulls
**
**
**
**
**
**
**
—
—
Source of variation
Between
years
**
**
**
0
0
**
**
0
0
Between
seasons
*
0
**
0
**
**
**
**
**
Interac*
tion
between
seasons
and
years
0
0
**
0
**
*
**
0
0
Between
months
within
season
0
0
0
**
**
0
**
—
—
** Significant at 1 per cent level
0 Non-significant
TABLE III
Critical difference at 5 per cent level of variable factors between years
Factors analysed
Reaction time in seconds
Volume in ml.
Initial motility of spermatozoa
Total number of spermatozoa ejaculate
Percentage of abnormal spermatozoa
Value of C.D.
5.92
0.26
0.15
313.63
0.77
Average of years arranged
in ascending order
45.33
1949-50
2.18
1949-50
3.57
1949-50
2,083.67
1949-50
6.62
1949-50
56.12
1950-51
2.67
1950-51
3.74
1950-51
2,473.61
1950-51
7.80
1950-51
Deceber, 1955 ] N. S. KUSHWAHA, D. P. MUKHERJEE AND P. BHATTACHARYA 321
Fig. 1. Monthly variation in reaction-time and semen qualities of buffalo-bulls with variation in air
temperature and relative humidity.