NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
ANIMAL NUTRITION AND GENETICS 61
REPRINTS.
The Pig Breeders' Annual.
Pig testing and recording for the purposes of advanced registry, by H. R.
Davidson and A. D. Buchanan Smith.
Scottish Journal of Agriculture.
1. Dual-purpose cattle. (Vol. X, No. 2.)
2. Pig Testing. The results of preliminary work on bacon type, by Alexander
Calder and A. D. Buchanan Smith. (Vol. XI, No. 3.)
3. Live-stock improvement and the scrub bull, by A. D. Buchanan. (Vol. XI,
No. 4.)
Quarterly Review of Biology.
Abnormal sexuality in animals, III sex reversal, by F. A. E. Crew.
Harper Adams Utilily Poultry Journal.
The influence of confinement on the production of white wyandotte pullets, by
Dorothy Macfadzean. (Vol. XIV, No. 12.)
Commercial methods of artificial brooding and rearing, by Raymond T.
Parkhurst. (Vol. XV, No. 5.)
A summer range shelter, by R. T. Parkhurst, assisted by E. W. Fogden and
Miss Mary McMurray. (Vol. XV, No. 8.)
Berkshire Milk Recording Society's Handbook (1928-29).
Milk secretion and milking, by Stephen Bartlett.
Journal of Genetics.
A case of lateral asymmetry in the domestic fowl, by F. A. E. Crew. (Vol.
XX, No. 2, November 1928.)
Farming News.
Prolificacy in beef cattle, by A. D. Buchanan Smith. (27th July 1927.)
Veterinary Journal.
Three cases of developmental intersexuality in the pig, by F. A. E. Crew,
(Vol. 79, No. 9.)
62 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, I
Developmental intersexuality in the domesticated goat, by F. A. E. Crew and
Adair Dighton. (Vol. 79, No. 4.)
The " Bull-Dog " calf of the dexter breed of cattle, by F. A. E. Crew.
Journal of Heredity (Organ of the American Genetic Association).
Inheritance of color, beard, tassels and horns in the goat, by S. A. Asdell
and A. D. Buchanan Smith. (Vol. 19, No. 9, September 1928).
Age and quality of offspring. The effect of age of parents on the quality of
offspring in cattle, by A. C. Choudhuri. (Vol. XVII, No. 10, October 1926 and
Vol. XIX, No. 9, September 1928.)
British Medical Journal.
The Mechanism of inheritance, lecture, by F. A. E. Crew. (August 14, 1926.)
The British Research Association for the woollen and worsted industries.
(Extracts from Publication No. 59, June 1926.)
1. Kemp in the fleece of the Welsh mountain sheep, by J. A. Fraser
Roberts.
2. Kemp fibres in fleeces of British breeds of sheep, by Janet. S. S. Blyth.
3. Studies of the fleeces fibres of British breeds of sheep, by Janet. S. S.
Blyth.
The Journal of the University College of Wales.
The science of genetics and its application to stock breeding, by F. A. E.
Crew.
Live-stock breeding research. Practical points, by A. D. Buchanan Smith.
The Journal of Anatomy.
A case of superfœtation in the pig, by A. D. Buchanan Smith. (Vol. LXI,
Part III, April 1927.)
Bibliographia Genetica.
The genetics of the horse, by F. A. E. Crew and A. D. Buchanan Smith.
(Vol. VI, 1930.)
Aberdeen Press and Journal.
The present agricultural station and how it may be improved, by Alexander
Caldar.
MGIPC—S3—III-1-136—16-3-31—1,000.
ORIGINAL ARTICLES
STATISTICAL STUDIES OF RECORDS OF INDIAN DAIRY CATTLE.
1. STANDARDISATION OF LACTATION PERIOD MILK RECORDS.
BY
LALL CHAND SIKKA, B.Sc. (AGRI.),
Punjab Government Research Scholar, Imperial Institute of Animal Husbandry and
Dairying, Bangalore.
(Received for publication on 12th March 1931.)
(With 5 charts.)
FOREWORD.
The above article may be classed as the first serious study on modern lines of
available statistics concerning Indian dairy cattle. The investigations which en-
abled the author to compile this article were made whilst he was a post-graduate
student at the Imperial Institute of Animal Husbandry and Dairying and the greater
part of his post-graduate study period at the Institute was taken up with this
important research work. Mr. Lall Chand has carried out this work so thoroughly
that it would be superfluous to attempt to describe what he has done in this fore-
word. His figures and deductions speak for themselves and indicate the spirit of
patient investigation and careful research so necessary in this class of research.
[WM. SMITH, Imperial Dairy Expert.]
INTRODUCTION.
The problems of Indian dairy cattle are highly complex and their solution
bristles with difficulties. A statistical study of India shows that India has far too
many cattle to successfully maintain them either for the work needs of the country
or for her food supply, and that there is a considerable economic loss owing to the
indiscriminate slaughter of cattle in cities. Besides, a comparison of the Indian
with foreign cattle as regards their efficiency to supply either of the above mentioned
needs reveals the fact that the majority of Indian cattle, judged by European
standards, are quite inefficient, and are only fit to be destroyed. This deplorable
state of affairs is mainly due to the actual cattle-breeding conditions existing in
( 63 )
A
64 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, II
India, for a very large number of cattle here have been bred from the maimed, the
undersized, the unfit and the starved parents, and are bound to be unfit and useless
animals according to the basic law of breeding—" Like begets like ".
Though the cattle of India measured by European standards are not economi-
cal or of first rate quality, they are without question the best tropical cattle in the
world. Their power to withstand epizootic diseases and ability to stand a hot
climate are factors of very great importance and value, and the best way of solving
the Indian cattle problem is to improve them without sacrificing these qualities. To
achieve this result it is necessary to establish and carefully maintain and breed herds
of the best Indian breeds and eliminate from them by a process of selection and
rejection all cattle below a certain fixed standard. This would gradually build up
profitable herds of indigenous cattle and is the direction in which the large land-
owners can best serve their country.
The process of selection, however, is not as simple as it looks. Taking only one
character, milk yield, for example, there are very great variations possible
in it owing to the effect of environmental variations. For a proper selection it
would be necessary that the effect of these environmental variations on milk yield
be eliminated, or the milk yield records be first standardised to a definite common
basis. Whereas a good deal of statistical work has been done in other countries in
this line and results of practical application to cattle-breeders have been obtained
therefrom, no attempt has to the author's best knowledge been made in this country
so far to investigate how the milk yield of the best Indian breeds is affected by
these environmental variations.
During the past 20 years a good deal of exact data regarding the milking capa-
bilities of hundreds of Indian dairy cows has been obtained on Military and other
Government farms. With a view to study the problem suggested above, a
statistical analysis of the vast amount of data available about Indian cattle
from these institutions offers to be a very fruitful line of research to a student
interested in cattle-breeding.
Within the last few years Hammond and Sanders [1923] from Penrith Milk Re-
cording Society data and Sanders from Norfolk Milk Recording Society data [1927, 1 ;
1927, 2 ; 1928, 1 ; 1928, 2], have conducted statistical studies of complete lactation
milk records of English cows with the object of standardizing these for the four
factors, season of year, service period, age, and dry period which mainly affect them.
No attempt was made to study the effect of variations in management, it being
assumed that this would be minimised for cows of the same herd. The eliminating
corrections obtained by Sanders for Norfolk data [1928, 2] are given in Table I.
STATISTICAL STUDIES, INDIAN DAIRY CATTLE
65
TABLE I.
Standardising corrections.
1. Month of calving
Standard—mean of all months
Month of calving
January .
February
March .
April
May
June
July
.
August .
September
October .
November
December
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Correction %
—0.9
2.8
0.2
2.2
+3.4
7.0
5.0
3.0
0.5
—4.7
2.6
3.8
2. Age,
Standard—maturity 6th lactation
Age
1st lactation
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Correction %
+30.6
18.0
9.3
3.7
0.7
..
+1.4
4.8
10.4
18.5
29.4
43.7
3. Length of service period
Standard—S. P.=85 days
Corrections
S. P. in days
0—19
20—39
40—59
60—79
80—99
100—119
120—139
140—159
160—179
180—199
200—219
220—239
240—259
260—279
280—299
380—399
480—499
1st calvers
+28.2
18.4
10.6
4.2
—1.1
5.5
9.2
12.4
15.2
17.6
19.7
21.5
23.1
24.5
25.8
30.5
33.3
Others
+23.9
21.3
11.9
4.6
—1.1
5.9
9.7
12.9
15.5
17.8
19.7
21.4
22.8
24.1
25.1
28.8
30.8
4. Length of dry period.
Standard—D. P. = 40 days
Corrections
D. P. in days
0—9
10—19
20—29
30—39
40—49
50—59
60—69
70—79
80—89
90—99
100—110
110—119
120 and Over
2nd calvers
+25.1
15.2
8.0
2.8
—1.3
4.4
6.4
8.8
10.4
11.7
12.7
13.5
14.8
Others
+14.0
8.8
4.7
1.5
—1.2
3.3
5.0
6.5
7.6
8.6
9.4
10.1
11.7
A similar study of Indian milk records was, therefore, undertaken exactly on
Sanders' lines, with the object of seeing how the elimination factors determined
from them differed from those of Sanders, and how Indian cows compared with
foreign cows in their milking capabilities. The results of this study for the first
three factors are given in pages to follow.
A 2
66 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, II
MATERIAL AND METHODS.
On all the Government dairy farms in India, two classes of animals have been
maintained, pure Indian and cross-breds. Of the pure Indian stock, the best and
most well managed herds and which consequently give the most reliable data for
such a study as this are the pure-bred Sahiwal herds at the Military Dairy Farms,
Lahore and Ferozepur, and at the Imperial Institute of Agricultural Research, Pusa.
Hence for the study of Indian cattle the milk records of the animals from these
herds only have been utilized.
But by far the greatest number of animals bred and kept on these farms is of
cross-breds. The milk records of the Military Dairy Farms' cross-breds, however,
suffer from a very serious defect, for most of these animals go on moving from place
to place along with troops, and consequently the milk-records produced by them
are affected by another very potent factor hard to allow for, i.e., change of locality
and therefore climate, etc. None of these is therefore used in studying the effect of
variation of these factors. The records of the Pusa cross-bred animals (1/2
Ayrshire-Sahiwal) which are free from this defect have been separately used in
studying the effect of age on lactation milk yield in that breed.
Only normal lactation milk records were utilized, all lactations being considered
abnormal and therefore excluded in which :—
(1) the cow failed to conceive again, and therefore in which S. P. could not
be found ;
(2) the calf was allowed to suck the cow ;
(3) there was any serious illness ;
and
(4) the cow aborted.
1496 complete lactation milk records from pure bred Sahiwals and 348 from
cross-breds were obtained and have been utilized for this study. Since Sanders'
work has shown that the effect of the season of the year varies from district to
district along with variations in herd management, only Lahore and Ferozepore
records—1274 in number—were used for this factor. It is much regretted that due
to the paucity and incompleteness of data in several respects the study of this
factor could not be very exhaustive. Though the results obtained may not be quite
conclusive, yet it may be said that a presumption has been laid that no such effect
of the season of the year on milk yield seems to exist in our data as reported by
Sanders. For the study of other factors all the 1496 records have been used. The
terms season of the year, service period, age, and dry period have the same
meaning as implied in Sanders' work.
67
Ordinary statistical methods as are necessary for the quantitative study of any
variable like milk yield have been used. To gauge the significance of a difference
probable error rather than the standard error has been used, a difference of less
than four times the probable error being taken in general as having arisen from
fluctuations of random sampling. This gives sufficiently high odds—142 : 1—
against such a difference having arisen due to fluctuations of random sampling.
DISCUSSION OF RESULTS.
Preliminary considerations. Since the problem being studied is that of
multiple correlation, it is but necessary to first study the distributions of different
factors and the interrelations so that firstly the best method of attack of the
problem may be selected and secondly due allowance may be made for any rela-
tions that exist.
Distributions. The distribution of the 1274 Ferozepur lactations according to
the month of calving is given in Table II.
TABLE II.
Month of calving
January
February
March
April
May .
June
July .
August
September
October
November
December
.
.
.
.
.
.
.
.
.
.
.
.
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.
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.
.
.
.
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.
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.
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.
.
.
.
.
.
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.
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.
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.
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.
.
TOTAL
No. of cows
calving
133
175
204
145
129
63
67
56
42
67
79
114
1,274
Per cent. of cows
calving
10.44
13.74
16.01
11.38
10.13
4.94
5.26
4.39
3.30
5.26
6.20
8.95
100.00
The figures are quite clear and require little comment. The percentage of
calving for different months goes on increasing quite regularly from October, in
which month only 5.26 per cent. of the total calved, to March, calving 16.01 per
cent. of total. From this there is a steady decline till September—calving 3.30 per
cent., the lowest for the year. This means that in these herds the largest number
of cows calve in spring and smallest in autumn months.
68
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, II
Service period in days.
Fig. 1. Distribution of service period.
STATISTICAL STUDIES, INDIAN DAIRY CATTLE
69
Figure 1 shows the frequency curve for the distribution of S. P. The mean
S. P. for these 1496 lactations is 123.8╤ 1.7 days median 91.78 days and the mode
lies at about 70 days. The standard deviation is 100.66 ╤ 1.2 days. Taking an
average gestation period of 280 days it will mean that the average cow in these
herds calves at an interval of 403.8 days or nearly every 13½ months, as against
1½ days less than a year for Sanders' [1927, 1] Norfolk data and 15½ days over a
year for the Penrith data [1923].
Table III gives the distribution of these records according to age as measured
in lactations.
TABLE III.
Lactation No.
1
2
3
4
5
6
7
8
9
10
11
12
Older
. . .
TOTALS
Percentage of total included
Our data
20.86
21.19
18.32
14.44
9.49
6.15
4.21
2.67
1.55
0.73
0.33
0.06
..
100.00
Penrith
34.3
28.5
18.1
10.3
5.1
1.9
0.9
0.7
0.15
..
0.05
..
..
100.00
Norfolk
23.5
20.9
17.6
13.6
9.6
6.1
4.2
2.3
1.2
0.5
0.1
0.1
0.1
100.00
It will be seen that in both our as well as Sanders' data the young cows are
much more numerous than the older ones. This is because good many cows are
kept in their early ages but are culled out later on due to poor production, only good
milkers—comparatively fewer in number—being maintained till older ages. The
average life of cows of our data is 3.37 lactations against Sanders 2.37 lactations
for Penrith and 3.27 lactations for Norfolk data.
Of the 1496 milk records included in this study, the length of the preceding dry
period is known only in the case of 1178 lactations, the distribution of which is
given in the form of a frequency curve in Figure 2.
70 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, I
Dry
period
in
days.
Fig. 2. Distribution of dry period.
STATISTICAL STUDIES, INDIAN DAIRY CATTLE
71
The mean length of preceding D. P. for these 1178 lactations is 119.74 ╤ 1.83
days, the standard deviation being 93.20╤ 1.30 days. This mean is, however,
much higher than Sanders' mean for mongrels (1167 observations) which is only
51.3 ╤ 0.69), showing thereby the uneconomic nature of our Indian cows due to
comparatively a greater part of their lives being useless.
Interrelations. The variation of S. P. and D. P. with the season of year, i.e.,
month in which a cow calves is shown in Table IV.
TABLE IV.
Showing variation of S. P. and D. P. with month of calving.
Month of calving
January
February
March
April
May
June
July
August
September
October
November
December
.
.
.
.
.
.
.
.
.
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.
Mean of 12 months
Mean S. P.
104.84╤ 4.69
114.42╤ 5.02
103.72╤ 3.63
111.98╤ 5.98
125.0 ╤ 6.41
136.48╤ 8.80
139.64╤ 11.93
130.22╤ 8.94
139.02╤ 14.45
121.44╤ 6.85
146.20╤ 10.17
121.96╤ 7.20
124.58
Mean D. P.
117.76╤ 6.87
112.52╤ 5.42
110.65╤ 3.50
113.88╤ 5.20
107.97╤ 5.19
126.50╤ 9.30
135.41╤ 11.05
122.90╤ 9.97
121.34╤ 10.62
125.36╤ 10.43
113.89╤ 6.60
105.56╤ 6.14
116.98
The variation of both S. P. and D. P. with the month of calving though slight
is quite significant. The S. P. is high for the months May to September—mean
being 132.24╤ 4.21 days, low for the months—January to April—108.62╤ 2.39
days, and about average for the other 3 months. The difference of 23 . 62╤ 4.84
days between the mean S. Ps. of months with low S. P. and high S. P. is quite
significant, it being 4.88 times its P. E. These results about the seasonal variation
of S. P. are quite in accord with those of Sanders who too found the S. P. to be
sub-normal for cows calving between February and June, and above the normal for
the remaining months, although this variation is much more pronounced in our
data than in his. The seasonal variation of S. P. has been interpreted by him as
physiological in the light of researches of Hammond [1927] regarding the effect
of the season of the year on the intensity and duration of oestrum.
72
THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY
[ I, II
The D. P. is above the normal for the months June to October—126.81╤ 4.68
and below the normal for the remaining months—mean 111.59 ╤ 2.02. The
difference of 15.22 ╤ 5.09 between these two means, however, is not significant as
it is only 2.99 times P. E. But since the figures for the variation of D. P. with
calving months are very smooth running, more reliance might be placed on the
differences between these monthly means than is indicated by their probable errors.
It will be noticed that this seasonal variation of D. P. coincides with that of S. P.
and since cows with long S. P. tend to have longer D. P. before they calve again
than those with short S. P., the longer D. P. for the cows calving in June to
October may partly be due to their longer S. P. This seasonal variation of D. P.
is different to that in Sanders' data in which the mean D. Ps. are lower than the
normal for the months July to October.
Table V shows the distribution of the milk records included in different calving
months according to the ages at which these records were made.
TABLE V.
Relation of month of calving and age % in lactations.
% Distribution in different ages of total.
Calving
month
January
February
March
April
May
June
July
August
September
October
November
December
Average
1st lac
tation
33.08
21.71
14.70
21.38
23.25
28.57
17.91
8.93
11.90
12.12
13.92
18.26
19.94
2nd
22.56
20.0
19.12
22.76
22.48
14.29
19.40
17.86
21.43
16.67
18.99
17.39
19.86
3rd
10.52
17.14
23.53
17.93
11.63
22.22
19.40
16.07
14.29
24.24
22.78
19.13
18.13
4th
14.29
13.14
12.75
12.41
15.50
7.93
14.92
14.29
28.57
19.70
21.52
14.78
14.76
5th
8.27
9.72
10.29
12.41
10.08
7.93
5.97
12.50
4.76
9.09
8.86
13.04
9.89
6th
6.01
7.43
5.88
4.14
8.52
7.93
10.45
7.15
9.52
6.06
6.33
4.35
6.59
7th
1.50
5.72
4.41
4.83
3.88
1.59
5.98
8.93
1.38
9.09
3.80
5.22
4.63
8th
2.26
2.86
3.92
3.45
1.55
1.77
1.49
10.72
..
1.51
2.53
3.48
3.14
9th
1.50
..
4.41
..
2.23
1.59
1.99
..
1.38
1.51
..
3.48
1.81
10th
..
1.41
0.49
0.69
..
3.18
1.49
1.78
1.38
..
1.26
0.87
0.87
11th
..
0.57
0.49
..
0.78
..
..
1.78
1.38
..
..
..
0.39
12th
..
0.57
..
..
..
..
..
..
..
..
..
..
0.08
Total
99.99
100.00
99.99
100.00
100.00
100.00
100.00
100.00
99.99
99.99
99.99
100.00
99.99
The percentage distribution of cows of different ages in different calving
months is far from uniform ; e.g., 1st calvers constitute 33.08 per cent. of the
total of January calvers, whereas in the months of April and September they
constitute only 21.38 and 11.99 per cent. respectively. This goes to show that
there exists in our data a relation between the age of cow and the month of
calving.
The correlation coefficients as derived from the correlation surfaces drawn
separately for the variable age and S. P. and age and D. P. were —.067 ╤ .017 and
STATISTICAL STUDIES, INDIAN DAIRY CATTLE
73
+ .0688 ╤ .0196 respectively. Neither of these two correlation coefficients is quite
significant according to our arbitrary standard of 4 times the P. E., for the 1st
value is only 3.94 times and the 2nd 3.51 times its probable error. But a care
ful study of the mean S. Ps. and D. Ps. for different ages revealed that these
relations though not quite significantly high are quite true. The mean S. Ps.
decrease quite regularly in our data, the means being 135.08 ╤ 3.90 days for
312 lactations of the 1st calf heifers, 129.18 ╤ 4.11 days for 317 records of the 2nd.
121.18 ╤ 4.03 for the 274 records of the 3rd lactation, 117.94 ╤ 3.28 for the 450
records for the 4th, 5th, and 6th lactations, and 108.78 ╤ 5.38 for the 137
records for the 7th, 8th, 9th and 10th lactations. This regular decrease in S. P.
is perhaps due to the effect of selection, only selected animals being maintained
in older ages.
The D. P. means for different ages, however, tended to increase slightly with
increase of age explaining thereby the reason for the positive value of r, e.g., the
mean D. P. preceding the 315 records of 2nd calvers was 107.2, for the 274 records
of 3rd calvers was 117.93 and for the 215 records of the 4th lactation was 127.47,
there being a similar increase with increase in age.
No relation seemed to exist in this data between the S. P. and D. P. preced
ing. The value of the correlation coefficient for these two variables was + .0763 ╤
.0195 or 3.91 times the P. E., which is not quite significant according to our
standard. Moreover since these two variables did not seem to increase or decrease
in any regular way, this low and rather insignificant value of r has been interpreted
as having arisen due to errors of simple sampling.
The foregoing discussion regarding the interrelations of the 4 factors, season
of the year, S. P., age and D. P. being studied here, leads us therefore to the
following conclusions :—
(1) There exist relations in our data between the month of calving and age,
S. P. and D. P.;
(2) The S. P. decreases slightly with advanced age ;
(3) The D. P. increases slightly with advanced age ;
and
(4) There is no relation apparent between the S. P. and D. P. preceding.
PROCEDURE EMPLOYED DURING THE STUDY.
As has been mentioned before, the problem being studied is that of multiple
correlation, hence the partial correlation method would be ideal provided the re
gressions permit its use on the basis of linearity. But as shall be shown later, such
a complete analysis of all the factors being studied at one time is not possible
since the regressions are decidedly non-linear. Consequently the method employed