a1 Institute for Agricultural Research, Ahmadu Bello University, Samaru, Zaria, Northern Nigeria
The importance of carotene supplements in the feeding of White Fulani Zebu cattle has been studied in three experiments. The live weight gains of heifers, with and without carotene on two planes of nutrition, showed 0·2 lb/head/day gain on the ‘high’ plane, but the ‘low’ plane group did not respond to carotene supplement. The association between cottonseed feeding and vitamin A deficiency, studied by comparing the rates of depletion of heifer calves on cottonseed supplements and on a sorghum/groundnut mixture, indicated that cottonseed can enhance the rate of carotene/vitamin A depletion in the liver. Carotene supplements equivalent to 2 oz red palm oil, to cows before and after calving failed to improve the vitamin A potency of milk. The total daily secretion of carotene and vitamin A in the milk was insufficient to maintain adequate liver stores in a suckled calf.
(Received October 17 1966)
p1 Present address: North of Scotland College of Agriculture, Aberdeen.