The effect of feeding shark-liver oil to cows on the yield and composition, and on the vitamin A and carotene content of the milk

An experiment with ten dairy cows has shown that the daily feeding of 30 or 60 g. of shark-liver oil containing 80,000 i.u. of vitamin A/g. is without effect on milk yield, fat yield, the fat and solids-not-fat percentage of the milk and on the health and wellbeing of the cow. 2. The concentration of aneurin, riboflavin and vitamin C in the milk was not affected by the feeding of shark-liver oil. 3. The total carotenoids of the milk fat decreased when shark-liver oil was fed. The vitamin A content of the fat increased 1100% when 30 g. were given and 1850% when 60 g. were fed. The highest individual value reached was 390 i.u./g. fat.