NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
134 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, II.
are more or less the same for the pedigree Sahiwal and the cross-bred, and it is
not unreasonable to prophesy that the pedigree Sahiwal would lose her reputation
for higher persistency when her level of production equals that of the cross-bred.
The cross-bred also would have shown the same persistency as the pedigree Sahiwal
if her production level had not been higher, as will be seen from the value of the
rate of decline against 750 lb. which is the average for the pedigree animal. And
indeed this has been found to be the case in a herd of 80 cross-bred cows of the
Northern Circle which show an average initial rate of yield of 740 lb. per month and
a rate of decline of 8.74 per 100 lb.
Table VII is valuable when persistency is made use of as the basis of testing if
feeding and management are adequate or not. It shows what percentage decline
may be normally expected at different levels of production. In making use of the
table it should be borne in mind that the levels of yield shown against the rates of
decline are productions at peak of lactation and not at any stage of it. Thus if a
cross-bred animal is found to yield 750 lb. in the 4th month of lactation the drop
in yield to be expected in the 5th month is not 8.465 of 750, but a higher percentage
appropriate to the yield at peak. The yield at peak could well have been 1,000 lb.
at which level the decline is about 10 per cent. So in all cases it is essential, when
estimating the probable fall, to look up and see what the animal yielded at peak
and find out the rate of decline corresponding to this level.
Table VIII shows the co-efficients of correlation between the three pairs of
characters: persistency and rate of yield, persistency and age, and age and rate of
yield. Persistency and rate of yield has been considered above. The relationship
TABLE VIII.
Co-efficient of correlation between pairs of variables :—Rate of decline, Rale of yield,
and Age.
Breed
Cross-bred cows . .
Pedigree Sahiwal . .
Ordinary Sahiwal . .
Buffaloes .
.
.
.
Co-efficient of correlation between
Rate of decline
and
rate of yield
0.4817
0.2598
0.4153
0.3499
Rate of decline
and age
0.2352
0.3595
0.2204
0.1500
Age and
rate of yield
0.1674
0.0639
0.2243
0.1516
PERSISTENCY AND ITS RELATION TO AGE AND LEVEL OF PRODUCTION
135
between age and persistency is weaker throughout except in the case of the pedigree
Sahiwal, and that between age and rate of yield is still weaker. The corre-
lation tables are given in the Appendix. The means of the values of persis-
tency for each age group are shown by the dotted lines in Fig. III, a to d.
Fig.III (a). Relation between ago and rate of decline, and age and level of production in cross-
bred cows.
Fig. III (6). Relation between age and rate of decline, and age and level of production in pedigree
Sahiwal cows.
D
136 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, II.
Fig. III (c). Relation between age and rate of decline, and age and level of production in ordinary
Sahiwal cows.
Fig. III (d). Relation between age and rate of decline, and age and level of production in buffaloes.
Broken lines show rate of decline, and continuous line, yield.
PERSISTENCY AND ITS RELATION TO AGE AND LEVEL OF PRODUCTION
137
They are found to be very irregular and the relationship is by no means linear.
The outstanding feature of these graphs is the marked rise, in all breeds except the
pedigree Sahiwal, from the first to the second lactation showing that heifers are
definitely more persistent than older cows. From the second to the third lactation
the rise is less marked, and thereafter the curves, though very irregular, generally
tend to be flat. The continuous line shows the mean initial rates of yield in the
various age groups, and it is interesting to observe that the irregularities in the
two are in the same direction, a fall in the rate of yield being followed by a fall
in the rate of decline, and vice versa. This suggests the explanation that persis-
tency is not influenced by age, but only by the level of production. The marked
rise from the first to the second lactation in the rate of decline is probably due
to the initial undeveloped condition of the udder, on account of which the
heifer starts with a low yield, but, as her udder is gradually developing, her milking
capacity also increases gradually, and this increase masks a portion of the decline
in milk yield. Her persistency, therefore, appears to be high.
Table IX shows the partial correlations between the variables, that is the net
correlation between two of the variables when the third is eliminated. When the
TABLE IX.
Co-efficients of partial correlation between any two of the variables: rate of decline,
rate of yield, and age, when the third is eliminated.
Breed
Cross-bred cows . .
Pedigree Sahiwal cows .
Ordinary Sahiwal cows .
Buffaloes .
.
.
.
Co-efficient of partial correlation.
Rate of decline
and
rate of yield
.4615
.2543
.3850
.3347
Rate of decline
and age
.1789
.3558
.1435
.1050
Age and
rate of yield
.0635
.0327
.1496
.1070
effect of the level of production is eliminated the correlation between age and persist-
ency becomes definitely insignificant. The pedigree Sahiwal is an exception to this
generalisation—the rate of decline actually decreases from the first to the third
lactation though the rate of yield is increasing. But no satisfactory explanation
could be offered for this departure. The number of observations in each group
are no doubt very small but so is the case in the ordinary Sahiwal where the rate
of yield and the rate of decline are found to follow the same trend.
D 2
138 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, II.
SUMMARY AND CONCLUSION.
Values of rate of decline are found for 812 lactations of the cross-bred cow, the
pedigree Sahiwal, the ordinary Sahiwal and the buffalo. The values are found
to lie within a range of 1 to 20 per cent. decline per month. The average rate of
decline varies from 8.6 per cent. in the case of the pedigree Sahiwal to 11.7 per
cent. in the case of the ordinary Sahiwal. The cross-bred and the buffalo show
9.2 per cent. and 9.7 per cent. respectively.
The rate of decline is found to increase with rise in the level of production.
Tables are given showing the percentage monthly decline to be expected at various
levels of production in the different breeds.
The rate of decline is found to increase definitely from the first to the second
lactation. From the second to the third the increase is less marked, and there-
after the curves tend to be flat. Beyond this no definite age—persistency relation
is indicated. The mean persistencies for each age group, though irregular, follow
the mean rates of yield for the same group very closely, indicating that persist-
ency is influenced more by level of production than by age.
REFERENCES.
Associates of Rogers (1928)—Fundamentals of Dairy Science.
John W. Gowen (1924)
...
Milk Secretion,
(also those cited in Part I).
APPENDIX I.
DETERMINATION OF THE MAXIMUM RATE OF YIELD AND THE RATE
OF DECLINE BY THE METHOD OF AVERAGES.
The example below illustrates the method of working when the number of
observations is 10. When the method of averages is employed it would be more
convenient and simple if an even number of observations is chosen. In all cases
the observations are divided into two equal halves as shown. These are added
up and the difference of the totals is found (total of second half is always sub-
tracted from total of first half). In the case of 10 observations this difference has
to be divided by 25 × .4343 to obtain the rate of decline per lb. per month.
With 8 observations the divisor is 16 ×.4343 and with six the divisor is
9 ×.4343. These are the cases ordinarily met with. But generally with n
observations the divisor would be n 2 /4 × .4343, where n is an even integer.
To find maximum:—When the number of observations is 10 (see example
below) 10/25 of the difference has to be added to total of first half. 1/5 of the
sum gives the log of maximum.
With 8 and 6 observations 6/16 and 3/9 respectively of the difference should
be added to total of first column and the sum divided by 4 and 3 respectively
to obtain log of maximum.
PERSISTENCY AND ITS RELATION TO AGE AND LEVEL OF PRODUCTION
139
EXAMPLE.
Determination of rate of decline by the method of averages
Time after
reaching
maximum
0.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Yield in
lbs. per
month
1,272
1,135
933
911
922
912
855
748
703
612
Logarithm of
yields
3.1045
3.0550
2.9699
2.9595
2.9647
2.9600
2.9320
2.8739
2.8470
2.7868
First half
3.1045
3.0550
2.9699
2.9595
2.9647
15.0536
Second half
2.9600
2.9320
2.8739
2.8470
2.7868
14.3997 (Totals.)
Difference (First half—Second half)=.6539
„
„
divided by 25
„ „ and
by .4343
=.02616
=.0602=The
rate of decline per lb. per month.
Maximum :—
Difference
.
.
.
.
10/25 of difference . . .
Adding to total of first half :- = 15.0536
= 15.3152
Divided by 5= 3.0630—
The maximum is :—
= .6539
= .2616
+ .2616
This is the loga-
rithm of the
maximum.
1156.
APPENDIX II.
Tables of Correlations:—
(a) Between Age and Persistency.
(b) Between Age and Level of Production
140 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, II.
TABLE I.
Correlation surface showing the relation of rate of decline to age. (Data :—Cross-bred
cows.)
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Rate of
decline
per
434.8 lb.
milk
Class
Mid-
point
—2.5
+2.5
7.5
12.5
17.5
22.5
27.5
32.5
37.5
42.5
47.5
52.5
57.5
62.5
67.5
72.5
77.5
82.5
87.5
92.5
Total .
Mean of each
Column
1
..
1
1
2
8
11
8
9
6
5
5
..
..
1
1
2
..
..
..
..
60
31.4
2
1
..
..
2
2
4
3
10
8
5
3
3
5
..
2
1
..
1
..
1
51
39.95
3
1
..
..
1
1
..
5
5
7
5
4
3
2
2
1
..
2
..
..
..
39
41.4
4
1
..
1
..
3
3
4
5
3
5
3
1
3
3
..
1
..
..
..
..
36
37.5
Age in lactations
5
..
1
..
1
..
1
1
3
8
3
5
5
3
1
..
1
..
..
..
..
33
42.4
6
..
..
..
..
2
1
3
2
3
3
..
1
1
1
..
..
..
..
..
..
17
36.3
7
..
..
1
..
1
3
..
2
1
1
2
2
..
1
. .
1
1
1
..
..
17
43.1
8
..
..
..
1
..
..
1
2
1
2
..
..
..
2
..
..
..
..
..
1
10
44.5
9
..
..
..
..
..
2
4
2
..
4
1
3
..
..
1
..
2
..
..
..
19
43.0
10
..
..
..
1
1
3
2
4
3
1
4
2
1
2
..
1
2
..
..
..
27
42.3
11
..
..
..
..
..
..
..
3
1
4
3
2
1
..
1
..
1
..
..
..
16
47.2
12
1
..
..
..
1
..
..
..
..
1
1
1
2
..
3
1
..
..
..
..
11
49.8
13
..
..
..
..
..
..
..
1
..
1
2
..
..
1
..
1
1
..
..
..
7
54.7
14
..
..
..
..
..
..
..
1
..
..
..
..
..
..
..
..
..
..
..
..
1
32.5
Tot al
4
2
3
8
19
28
31
49
41
40
33
23
18
14
9
9
9
2
..
2
344
Mean age . . .
Mean rate of decline
5.07 lactations.
39.99 lb. per month per
434.3 lb. milk.
Standard deviation of age .
Standard deviation of decline .
Coefficient of correlation
. .2352
3.58 lactations.
17.20 lb.
PERSISTENCY AND ITS RELATION TO AGE AND LEVEL OF PRODUCTION
141
TABLE II.
Correlation surface showing the relation of rate of decline to age. (Data :—Pedigree
Sahiwal.)
Rate of de-
cline per
434.3 lb.
milk
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Class
Mid-
point
—2.5
+2.5
7.5
12.5
17.5
22.5
27.5
32.5
37.5
42.5
47.5
52.5
57.5
62.5
67.5
72.5
77.5
82.5
87.5
92.5
97.5
102.5
107.5
Total .
Mean of each
Column
1
3
1
..
..
..
3
..
2
1
4
1
1
..
..
..
..
..
..
..
..
..
..
..
16
27.2
2
..
1
..
1
1
4
3
2
..
..
..
..
1
..
..
..
..
..
..
..
..
..
..
13
25.2
3
..
..
1
1
3
2
1
..
1
..
..
..
..
..
..
..
..
..
..
..
..
..
..
9
20.3
4
..
..
..
1
..
3
2
..
1
2
1
..
1
2
..
..
..
1
..
..
..
..
..
14
37.8
Age in lactations
5
..
..
..
..
..
1
..
4
2
..
1
..
..
2
..
1
..
..
..
..
..
..
..
11
43.0
6
..
1
..
..
..
..
1
2
2
..
..
..
1
1
..
..
..
..
1
..
..
..
..
9
42.0
7
..
..
..
..
1
..
1
..
2
2
..
..
2
1
1
..
..
..
..
..
..
..
..
10
45.0
8
..
..
1
..
1
..
..
2
3
..
..
..
1
..
..
..
..
..
1
1
..
..
..
10
44.0
9
..
..
..
..
1
1
..
..
1
..
2
..
..
..
..
..
..
..
..
..
1
..
..
6
45.0
10
..
..
..
1
..
..
..
..
..
..
2
1
1
..
..
..
..
..
..
..
..
..
..
5
43.0
11
..
..
..
..
..
2
..
..
1
..
..
..
..
..
..
..
..
..
..
..
..
..
1
4
47.0
12
..
..
..
..
..
2
..
..
..
..
..
..
..
..
..
1
..
..
..
..
..
..
..
3
39.1
13
..
..
..
..
..
..
..
..
..
..
1
..
..
..
..
..
..
..
..
..
..
..
..
1
47.5
14
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
1
..
2
67.5
Total
3
3
2
4
7
18
8
13
14
8
8
2
7
6
1
2
..
1
2
1
1
1
1
113
Mean age
.
.
.
.
5.39
Mean rate of decline
.
37.4555
Coefficient of correlation
Standard deviation
Standard deviation
. . .318
. . 3.37
. . 22.04
142 THE INDIAN JOURNAL OP VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, 11.
TABLE III.
Correlation surface showing the relation of rate of decline to age, ( Data :—
Sahiwal cows.)
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Rate of
decline
per 434.3
lb. milk
Class
Mid-
point
2.5
7.5
12.5
17.5
22.5
27.5
32.5
37.5
42.5
47.5
52.5
57.5
62.5
67.6
72.5
77.5
82.5
87.5
92.5
97.5
102.5
107.5
112.5
117.5
122.5
127.5
Total .
Mean
of each
column.
1
1
1
...
1
2
1
1
...
...
...
...
...
...
1
...
...
...
...
...
...
...
...
...
...
...
...
8
25.0
2
...
...
...
1
1
2
...
1
2
1
1
2
...
...
...
1
...
1
..
...
1
...
...
...
...
...
14
50.0
3
...
...
...
2
...
...
2
2
...
3
...
3
2
...
...
1
2
...
...
...
...
...
...
...
...
...
16
50.0
4
...
...
...
3
...
3
...
1
1
...
2
...
2
1
1
...
1
...
...
...
...
..
...
...
...
1
16
49.7
6
...
1
...
1
...
...
...
...
1
...
2
1
2
2
1
...
...
1
...
...
...
...
...
...
...
...
16
48.8
Age in lactations
6
...
...
...
...
...
2
...
...
...
...
...
...
1
1
...
1
...
1
...
1
..
1
...
...
...
...
10
64.5
7
...
...
...
1
...
1
...
1
1
1
...
2
...
...
...
...
1
...
...
...
...
...
...
...
...
...
8
45.3
8
...
...
...
...
...
1
...
2
1
...
...
1
1
1
...
...
...
...
...
...
...
...
..
...
...
...
7
47.5
9
...
...
...
...
1
...
...
...
...
1
1
1
...
1
...
2
...
...
...
...
...
...
...
1
...
...
8
65.6
10
...
...
...
...
...
...
...
...
...
1
2
...
...
...
1
...
...
...
...
...
...
...
...
...
1
...
5
69.5
11
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
12
...
...
...
...
...
...
...
1
...
...
...
1
...
1
...
...
...
...
...
...
...
...
...
...
...
...
3
54.5
13
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
14
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
Total
1
2
...
9
5
11
4
8
7
9
8
10
8
8
3
5
4
3
...
1
1
1
...
1
1
1
111
...
Mean age . . . . . . 5.0270
Mean rate of decline . . . . 50.92
Coefficient of correlation .
Standard deviation
Standard deviation
. . .
. . . . . 2.749
. . . . . 25.065
.260
PERSISTENCY AND ITS RELATION TO AGE AND LEVEL OF PRODUCTION
143
TABLE IV.
Correlation surface showing the relation of rate of decline to age. (Data :—Buffaloes.)
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Total
Rate of
decline
per 434.3
lb. milk
Class
Mid-
point
-2.5
+2.5
7.5
12.5
17.5
22.5
27.5
32.5
37.5
42.5
47.5
52.5
57.5
62.5
67.5
72.5
77.5
82.5
87.5
92.5
97.5
102.5
107.5
112.5
. .
Mean of each
column
1
...
...
2
...
...
2
3
...
1
...
2
...
...
...
...
...
...
...
...
...
...
...
...
10
27.5
2
...
...
1
3
...
2
3
5
10
7
5
5
4
1
...
1
2
...
...
...
...
...
...
49
41.4
3
3
...
2
1
...
3
4
5
9
4
6
4
2
2
1
...
1
...
1
...
...
...
...
...
47
39.1
4
...
...
1
...
1
5
5
3
5
5
4
1
2
2
...
2
2
1
...
...
...
...
...
1
40
43.8
5
...
...
...
...
...
...
1
2
3
2
7
...
1
1
2
...
...
...
...
...
...
...
...
19
46.2
Age in lactations
6
...
...
...
...
...
1
3
...
6
1
3
...
3
1
1
1
...
...
1
...
...
...
...
...
21
46.6
7
1
...
...
...
...
1
2
3
3
5
1
1
1
1
...
...
...
...
...
...
...
1
...
...
20
41.0
8
...
...
...
...
...
1
1
1
6
2
...
3
...
...
1
1
1
...
...
...
...
...
...
16
44.7
9
...
...
...
...
1
...
1
1
2
...
2
2
...
1
...
...
...
...
...
...
...
...
...
...
10
41.5
10
...
...
...
...
...
...
...
2
1
...
...
...
...
1
...
...
...
...
...
...
...
...
...
1
5
55.5
11
...
...
...
...
...
...
...
...
...
...
...
...
...
...
2
...
...
...
...
...
...
...
...
2
67.5
12
...
...
...
...
...
1
...
1
...
1
...
...
1
...
...
...
...
...
...
...
...
...
...
...
4
38.9
13
...
...
...
...
...
...
...
...
...
...
...
1
...
...
...
...
...
...
...
...
...
...
...
...
1
52.5
14
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
...
Total
3
...
6
4
2
16
23
23
46
27
30
16
14
10
7
5
6
1
2
...
...
1
...
2
244
...
Mean age
.
.
.
.
.
4.5943
Mean rate of decline
. . . 42.2705
Standard deviation
. . . 2.601
Standard deviation
. . . 17.890
Coefficient of correlation .
.
.
.1500
144 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, II.
TABLE V.
Correlation surface showing the relation of rate of yield to age. (Data :—Cross-bred
cows.)
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Rate
of
Yield in
100 lb.
unit
Class
Mid-
point
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.6
9.5
10.5
11.5
12.5
13.5
14.5
15.5
16.5
17.5
18.5
19.5
20.5
21.5
22.5
23.5
24.5
Total .
Mean yield
per month.
1
..
..
2
4
5
8
14
7
7
6
2
3
1
1
..
..
..
..
..
..
..
..
..
..
60
812
2
..
..
..
4
2
4
8
8
6
6
3
2
5
1
..
..
1
1
..
..
..
..
..
..
51
942
3
..
1
..
1
2
5
5
3
5
4
4
2
2
2
..
1
..
1
..
..
..
..
..
1
39
999
4
..
..
..
4
2
1
5
6
2
4
4
..
3
1
3
..
..
1
..
..
..
..
..
..
36
975
5
..
..
..
2
1
2
3
2
4
3
4
4
1
3
..
1
2
..
..
1
..
..
..
..
33
1096
Age in lactations
6
..
..
..
1
..
1
2
1
5
1
3
1
..
1
..
1
..
..
..
..
..
..
..
..
17
1003
7
..
..
1
1
..
1
3
2
2
3
2
..
..
..
..
..
..
..
1
1
..
..
..
..
17
985
8
..
..
..
..
..
..
1
..
2
4
1
1
..
..
..
..
..
1
..
..
..
..
..
..
10
1110
9
..
..
..
1
2
2
..
2
1
3
2
2
1
2
..
1
..
..
..
..
..
..
..
..
19
1018
10
..
1
1
1
..
2
3
5
2
1
2
1
..
5
1
1
1
..
..
..
..
..
..
..
27
1020
11
..
..
..
..
..
..
3
..
5
3
2
2
..
..
..
..
..
..
..
..
..
..
..
..
16
1038
12
..
1
..
..
..
..
1
1
1
3
2
..
1
1
..
..
..
..
..
..
..
..
..
..
11
1005
13
..
..
..
..
..
..
..
1
..
1
2
2
1
..
..
..
..
..
..
..
..
..
..
..
7
1150
14
..
..
..
..
..
..
..
1
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
..
1
850
Total
...
3
4
19
14
28
48
39
42
42
83
20
15
17
4
6
4
4
1
2
—
—
—
1
344
Mean age
.
.
.
.
.
5.06686
Mean rate of yield per month at
maximum
.
.
.
. 974.70 lb.
Standard deviation
. . . 3.579
Standard deviation . . . 357.1 lb.
Coefficient of correlation
.
.
1674
PERSISTENCY AND ITS RELATION TO AGE AND LEVEL OF PRODUCTION
145
TABLE VI.
Correlation surface showing the relation of rate of yield to age. (Data :—Pedigree
Sahiwal.)
No.
1
2
3
4
5
6
7
8
9
Rate
of
Yield
per
day
Class
Mid-
point
2.5
7.5
12.5
17.5
22.5
27.5
32.5
37.5
42.5
Total .
Mean yield
per day.
Mean yield
per month
lb.
1
1
1
5
2
3
4
..
..
..
16
25.6
716
2
..
..
..
..
4
4
4
1
..
13
27.7
774
3
..
..
..
..
1
6
2
..
..
0
27.6
773
4
..
..
..
2
1
4
3
3
1
14
28.0
784
5
..
..
..
..
1
5
2
1
2
11
28.3
793
Age in lactations
6
..
..
..
1
..
3
..
4
1
9
28.5
798
7
..
..
..
3
2
1
..
4
..
10
27.5
770
8
..
2
1
..
1
4
2
..
..
10
26.5
742
9
..
1
..
..
3
1
1
..
..
0
26.5
742
10
..
..
..
1
2
1
1
..
5
26.9
753
11
..
..
..
1
..
1
2
..
..
4
27.5
770
12
..
..
..
..
..
2
1
..
..
3
27.8
779
13
..
..
..
1
..
..
..
..
..
1
25.5
714
14
..
..
..
1
..
..
1
..
..
2
27.0
756
Total
1
4
6
12
18
36
19
13
4
118
..
..
Mean age
.
.
.
.
.
.
5.3894
Mean rate of yield per day at maximum . 26.438 lb.
Standard deviation .
. . 3.369
Standard deviation .
. . 8.295 lb.
Coefficient of correlation
.
.
.0639
146 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ IV, II.
TABLE VII.
Correlation surface showing the relation of rate of yield to age.
(Sahiwal cows.)
No.
1
2
3
4
5
6
7
8
9
Rate of
yield in
100 unit
lbs.
Class Mid-
point
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
9.5
Total .
Mean rate
of yield
in lbs.
1
..
3
3
2
..
..
..
..
..
8
338
2
..
2
2
5
2
2
1
..
..
14
471
3
..
1
3
4
3
2
3
..
..
16
519
4
..
1
2
2
6
2
2
1
..
16
551
Age in lactations
5
..
1
3
5
4
2
1
..
..
16
488
6
..
..
1
4
1
3
..
1
..
10
550
7
..
1
2
2
1
2
..
..
..
8
463
8
..
..
1
2
3
1
..
..
..
7
507
9
..
..
..
5
1
..
1
..
1
8
563
10
..
..
..
..
3
1
1
..
..
5
610
11
..
..
..
..
..
..
..
..
..
..
..
12
..
..
..
1
2
..
..
..
..
3
517
13
..
..
..
..
..
..
..
..
..
. .
..
Total
..
9
17
32
20
15
9
2
1
111
..
Mean age . . . . . . 5.027
Mean rate of yield per month at max. . 504.955 lbs.
Standard deviation . . . . 2.749
Standard deviation . . . . 148.1 lbs.
Coefficient of correlation
. . . . . .2243
PERSISTENCY AND ITS RELATION TO AGE AND LEVEL OF PRODUCTION
147
TABLE VIII.
Correlation surface showing the relation of rate of yield to age. (Data—Buffaloes.)
No.
1
2
3
4
5
6
7
8
9
10
11
12
Rate of
yield in
100 lb.
unit
Class Mid-
point
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10.5
11.5
12.5
Total .
Mean yield per
month lb. .
1
1
1
2
3
1
1
..
1
..
..
..
..
10
450
2
..
1
3
8
10
15
8
2
2
..
..
..
49
607
3
..
1
2
7
10
17
7
2
1
..
..
..
47
607
4
..
..
3
3
14
7
6
3
4
..
..
..
40
638
5
..
..
..
..
5
6
7
..
..
..
..
..
19
687
Age in lactations
6
..
..
2
5
2
3
7
1
1
..
..
..
21
621
7
..
..
..
5
4
3
4
4
..
..
..
..
20
640
8
..
..
1
4
2
3
2
3
1
..
..
..
16
639
9
..
..
1
3
1
2
1
1
1
..
..
..
10
610
10
..
..
..
1
3
..
..
..
1
..
..
..
5
610
11
..
..
..
..
1
1
..
..
..
..
..
..
2
600
12
..
..
..
1
1
1
..
..
1
..
..
..
4
650
13
..
..
..
..
..
..
..
..
..
..
..
1
1
l.250
Total
1
3
14
40
54
59
42
17
12
..
1
1
244
Mean of age .
.
.
.
.
4.5943
Mean rate of yield per month at max. . 621.31 lb.
Standard deviation
.
.
.
.
.
2.601
Standard deviation
.
. . . . 165.9 lb
Coefficient of correlation
.
.
.
.
.1516
ON THE OCCURENCE OF SCHISTOSOMA JAPONICUM
KATSURADA IN INDIA.
BY
G. D. BHALERAO, M.Sc.,
Helminthologist, Imperial Institute of Veterinary Research, Muktesar.
(Received for publication on the 10th April 1934.)
With one text-figure.)
Through the courtesy of Dr. P. A. Maplestone an opportunity was afforded to
examine some schistosomes obtained from the intestine of a pig in Calcutta. Only
about half a dozen male specimens in poor state of preservation were received and
these were studied in toto preparations only. No female was represented in the
collection.
The male worms measure 5.65—6.62* in length and their maximum thickness
varies from 0.183 to 0.258. The cuticle of the body is entirely covered with
tubercles of moderate size bearing a varying number of minute spines on their
summit. The number of the spines on these tubercles vary from 1 to 8, indicating
that they are easily lost during manipulation. It was not unusual to find some of
the tubercles entirely bereft of the spines. In addition to these tubercles the ventral
surface of the body is covered with minute spines.
The subterminal oral sucker measures 0.147—0.167 × 0.137—0.153. The pedun-
culated ventral sucker is 0.16—0.167 in diameter and 0.053—0.06 in thickness.
Both the suckers are covered with minute spines and the distance between them is
0.263—0.293. The funnel-shaped mouth leads into the œsophagus measuring 0.31—
0.32 in length. The intestinal cæca unite at a point somewhere between one-fourth
and one-third of the body length from the posterior extremity. The common
intestinal cæcum terminates at about 0.132 from the posterior end of the body.
The testes are seven in number and measure 0.052—0.1 × 0.052—0.094. They
extend posteriorly for a short distance from the commencement of the gynæcophoric
canal. When observed laterally under high magnification five of them, viz., the
first, third, fifth, sixth and the seventh appear at one level and the remaining two,
viz., the second and the fourth appear to be situated at a slightly different level.
The vesicula seminalis appears to be an oblong sac, measuring 0.047—0.05 × 0.024
—0.033 and opens to the exterior by a short canal.
* All measurements in millimeters.
( 148 )