Factors influencing the vitamin content of milk fat. III. The source of milk fat vitamin A and carotene
Jour Dairy Res 24(1): 102-107
The effect of varying levels of vitamin A ester in blood plasma of cows on the levels of vitamin A ester in their milk was investigated by administering oral doses of vitamin A ester after a period of feeding a vitamin A- and carotene-free ration. The milk fat levels reflect plasma levels, but some of the milk fat vitamin A ester appeared to be derived from other than immediate dietary origin. The bulk of the plasma carotene apparently contributes little to the carotene of milk fat. The carotene of milk fat seems to derive mainly from carotene of immediate dietary origin.