Mammary transfer of vitamin E in dairy cows.

Milk vitamin E from eight dairy cows was analyzed for vitamin E by HPLC during the 1st mo of lactation. Colostrum gave a mean value of 1.9 micrograms alpha-tocopherol/ml while concentrations of fresh milk averaged .3 microgram alpha-tocopherol/ml. D-gamma-tocopherol concentrations were observed in very small amounts. When six cows at the end of the 1st mo of lactation were injected intraperitoneally with an emulsion of dl-alpha-tocopherol acetate (5 g), plasma and milk concentrations of alpha-tocopherol were increased from their original values of 4.5 micrograms/ml plasma and .3 microgram/ml fresh milk to 10.9 micrograms/ml plasma and 1.6 micrograms/ml fresh milk, 12 h later. The results show that intraperitoneal administration of vitamin E to dairy cows in an effective way of increasing plasma and milk tocopherol concentration.