186
Vitamin C Content of Milk
dichlorophenol indophenol and vitamin C expressed as mg. of ascorbic acid per litre of milk. From
a few preliminary trials it was found that fresh milk collected in dark bottles contained only a very
negligible amount of reversibly oxidised ascorbic acid. The same observation was made by Ray
et al [1941]. Hence only the reduced ascorbic acid was estimated in the experimental samples. The
estimation of the vitamin was carried out every week for about 12 months when most of the animals
went dry. The average vitamin C content of the milk of each breed for each month is calculated
and presented in Table I.
TABLE I
Average vitamin C content in mg. per litre of the milk of different breeds
Month
November
.
.
.
.
December
.
.
.
.
January .
.
.
.
.
February .
.
.
.
.
March
.
.
.
.
.
April
.
.
.
.
.
May
.
.
.
.
.
June
.
.
.
.
.
July
.
.
.
.
.
August
.
.
.
.
.
September
.
.
.
.
October
.
.
.
.
.
Average for the lactation exclud-
ing the first month
Sindhi
18.1
23.1
22.9
25.6
21.8
22.1
21.4
20.0
26.8
28.4
30.0
..
24.2
Gir
18.0
19.5
22.8
23.5
20.8
20.4
19.0
19.4
21.1
24.6
25.6
26.4
22.1
Tharparkar
19.1
19.2
20.1
21.6
19.7
19.4
18.5
20.0
20.0
19.6
..
..
19.8
Cross-bred
21.4
21.1
20.1
20.8
20.8
17.5
19.0
17.4
20.7
20.2
22.9
23.2
20.4
Murrah
13.1
21.2
28.5
27.7
27.7
27.0
24.5
24.5
26.3
25.2
..
..
25.6
Herd average
for the month
(Cow and
buffalo)
16.2
19.8
22.9
22.2
22.2
21.3
20.3
20.3
23.6
23.2
26.2
24.8
22.6
DISCUSSION
It was noticed that in the case of all except cross-bred cows, the average vitamin C content of
milk in the first month of lactation was slightly lower than the average value for each of the other
months. These figures were also lower than the breed average or the herd average for the whole
lactation. This is an agreement with the findings of Whitnah and Riddel [1937].
After the first month of the lactation, there was a gradual increase in the vitamin C content
of the milk of all except cross-bred cows. This increase continued till the fourth month and there-
after the values began to decline till the end of the eighth month when an increase was observed
which was kept up till the end of lactation. In the case of the cross-bred cows, from the very first
month, the values for vitamin C declined gradually till the eighth month when an upward trend
occurred and this was maintained till the end of the lactation.
The fluctuations observed in the vitamin C content of milk cannot be attributed to feed, since,
the animals were receiving more-or-less the same feed throughout the experiment. Of the other
factors that might influence the vitamin C content one is the season. In the present investigation
two peak levels were observed, one in February and a still greater one in September, but in view of
the more or less uniform climate of Bangalore, it may be reasonable to attribute these changes in
vitamin C content of milk to lactational changes only.
It will be observed that breed variations in the vitamin C content of milk are quite marked.
The average vitamin C content of the milk of the different breeds of Indian cattle as observed in the
present investigation compares very favourably with the figures reported by foreign workers for the
milk of European breeds.
Individual variations are observed in the vitamin C content of milk. In the case of the milk of
Sindhi cows figures ranging from 21.9 mg. to 48.8 mg. of ascorbic acid per litre have been observed,
but generally the range is much smaller. In the case of the other breeds also more or less the same