PREDICTION OF MILK YIELDS
221
TABLE II
Showing the variation in the ratio of total yield for ten months to the yield per month
in the various months of lactation, when the rate of decline per lb. per month
changes from .01 to .20.
Rate of decline
per lb. per
month
.01
.02
.03
.04
.05
.06
.07
.08 a
.09
10 b
.11
.12 c
.13
.14
.15
.16
.17
.18
.19
.20
Months of lactation
1
9.61
9.24
8.90
8.58
8.27
7.98
7.71
7.46
7.21
6.98
6.77
6.57
6.37
6.19
6.02
5.86
5.69
5.54
5.40
5.27
2
9.71
9.43
9.17
8.93
8.69
8.48
8.27
8.08
7.89
7.72
7.56
7.40
7.26
7.12
6.99
6.87
6.74
6.63
6.53
6.44
3
9.80
9.62
9.45
9.30
9.14
9.00
8.87
8.75
8.64
8.53
8.44
8.35
8.26
8.19
8.12
8.07
7.99
7.94
7.90
7.86
4
9.90
9.81
9.73
9.67
9.61
9.56
9.51
9.48
9.45
9.43
9.42
9.41
9.41
9.42
9.44
9.46
9.47
9.50
9.55
9.60
5
10.01
10.02
10.03
10.07
10.10
10.16
10.21
10.27
10.34
10.42
10.52
10.61
10.72
10.83
10.96
11.11
11.22
11.38
11.54
11.73
6
10.10
10.22
10.34
10.48
10.62
10.78
10.95
11.13
11.32
11.52
11.78
11.96
12.20
12.47
12.74
13.03
13.29
13.62
13.96
14.33
7
10.21
10.42
10.65
10.91
11.16
11.45
11.74
12.05
12.38
12.73
13.10
13.49
13.90
14.34
14.79
15.30
15.76
16.31
16.89
17.50
8
10.32
10.64
10.97
11.36
11.74
12.16
12.59
13.05
13.55
14.06
14.62
15.21
15.83
16.49
17.19
17.95
18.68
19.53
20.42
21.38
a
b
c
These are the most appropriate figures for use with specially bred Indian cows.
„
„
„
„
„ „
„ „
cross-bred cows and buffaloes.
ordinary Indian cows.
FOOT-NOTE TO TABLE II.
NOTE 1.—By means of this table the total yield for ten months can be estimated from a knowledge
of the yield for any month of lactation. This is done by multiplying the known monthly yield by one
of the ratios tabulated. The appropriate ratio to take depends on the stage of lactation (i.e., 1st, 2nd,
3rd, etc., month after calving) and the rate of decline. If the latter is known the ratio is obtained by
running the eye down the column for the month of lactation, to which the yield pertains, and against
the value of decline. If the decline is not known this may be assumed to be the average for the class
of animals to which the herd belongs. This is .08 for specially bred Indian cows, .10 for cross-bred
cows and buffaloes and .12 for the ordinary Indian cow. The values for these classes are printed in
bold type.
Example—
If a buffalo yields 400 lb. of milk during the third month of lactation how much will she yield in
ten months ? For buffaloes the rate of decline is .10. Against this value the ratio is 8.53 in the column
for 3rd month. The yield for 10 months is therefore 400 × 8.53 or 3412 lb. If she yields 300 lb. in the
6th month her total yield for 10 months Will be 300 × 11.52 or 3456 lb.
Similarly if an ordinary Indian cow yields 4.00 and 300 lb. in the third and sixth month of lactation,
her ten months. yields will be 400 × 8.35 or 3340 lb. and 300 × 11.96 or 3578 lb. respectively.
NOTE 2.—In estimating stage of lactation, the month of calving should be omitted. Thus if a cow
calves in June, July is her first month of lactation, August second month, September third month
and so on.
NOTE 3.—The peak of lactation is generally reached between the 3rd and the 6th week after calving,
and if the yield for these four weeks is known, yield for a lactation of 300 days is approximately obtained
by multiplying the average daily yield for these four weeks by :—
223.8 in the case of specially bred Indian cows.
209.4 in the case of buffaloes and cross-bred cows.
197.1 in the case of ordinary Indian cows.