Placental and Mammary Transfer of Vitamin A and Carotene by Beef Cows

Summary Beef cows receiving a carotene allowance equivalent to 60 /xg per pound of body weight daily were unable to maintain liver stores or plasma vit. A levels during the last 6 months of gestation. When the carotene allowance was increased to 333 /xg during lactation, liver stores and plasma vit. A were increased. Vit. A in the plasma and liver of the calf was closely associated with the carotene intake of the dam during lactation, but was also influenced by the liver stores of the cow at parturition.