S. V. DESAI AND M. L.
MATHUR
209
in the premilk was as high as 1 : 3.64 and, when the
percentage of calcium and phosphorus appeared to
remain constant after calving, the ratio was
1:1.18.
It was interesting to note that the highest ratio
of CaO : P 2 O 5 was found on the very first or second
day of premilk. As 'Felbir' was already giving
premilk, the highest ratio was not observed as in
the case of 'Narajkhati.' This explained the dis-
similarity in the curves of the graphs of the two
cows in the first few days. If the part of the curves
of Narajkhati's graph for the first few days is not
considered, the curves in those of the two premilkers
are similar. The high ratio of the salts in 'Naraj-
khati's' milk indicated more secretive power.
Two high milkers and five medium and low milkers
in the first, second and third hundred days of lacta-
tion were selected. In 'Tashkam' with a yield of
31 pounds per day the percentage of calcium and
phosphorus was low as compared to the others. In
the individual cows, there was not much variation
in the percentages of calcium and phosphorus in
the course of four weeks. In all the first calvers
the composition of each cow's milk was different
from that of the other. In the third 100 days of
lactation, when the yield was low and the cow was
completing lactation, the milk was generally richer
in mineral contents. It was of interest to note
that in 'Taroochi' and 'Folgai' with the same
yield (22 pounds) and in the same stage of lactation,
the percentage of calcium and the phosphorus was the
same.
Four high milkers and three medium and low
milkers in the first and second 100 days of lactation
were available. In all the cows except diseased
ones, there was not much variation in the percent-
ages of calcium and phosphorus in the course of
four weeks. The composition of the milk of the
different cows varied. In 'Rajudhina' the calcium and
phosphorus percentage was rather high for some
time when she was suffering from foot-and-mouth
disease. It decreased as the cow came to normal
health. In some cases, with the decrease in yield
in the later part of lactation, the calcium percentage
increased.
Four high and four low milkers in the first, second
and third 100 days of lactation were selected. 'Raj-
lari' also was affected with foot-and-mouth disease
and this accounted for the high amount of calcium
and phosphorus in the milk for some time. The
percentage of calcium and phosphorus fell later on
when the cow was normal.
A comparison of the data of two cows 'Rajsam'
and 'Lakroochi' in the first 100 days and second
100 days of lactation (in Table IX) revealed that:
(1) During the flush (peak) period when the yield
reached the maximum, the percentages of calcium
and phosphorus were appreciably lower than those
at a later period when the yield fell by 12-16 pounds;
(2) The ratio of calcium to phosphorus was practi-
cally the same; and
(3) The total amount of calcium and phosphorus
output in the milk per day also fell with the yield.
There were chances of positive balances being main-
tained and storage if the rations were not much
reduced.
TABLE VIII
Comparative figures for calcium and phosphorus ratio amongst, adults
Names of cows
Narbila
Rajkhati
Lakholmi
.....
Rajsam
.....
Choreng
.....
Rajarama
Rajsuri
Rajlari
Average
yield
of milk
per day
in lb.
37
37
34
28
16
15
12
6
CaO per-
centage
in milk
0.165
0.159
0.163
0.167
0.165
0.157
0.165
0.185
0.198
P 2 O 5 per-
centage
in milk
0.201
0.174
0.189
0.213
0.237
0.228
0.225
0.264
0.273
Ratio
CaO:
P 2 O 5
1 : 1.21
1 : 1.09
1 : 1.15
1 : 1.27
1 : 1.43
1 : 1.45
1 : 1.34
1 : 1.37
1.25
Stage of lactation
1st 100 days
2nd 100 days
3rd 100 days