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

Publisher Website
Google Scholar
Abstract
Two-year-old Hereford cows receiving a carotene allowance equivalent to 60 [mu]g./lb. of body wt. in the form of a crude carotene concentrate prepared from alfalfa were unable to maintain liver stores (as detd. by liver biopsy) or plasma levels of vit. A during the last 6 mos. of gestation. When the carotene intake was increased to 333 [mu]g. during lactation, liver stores and plasma levels of vitamin A were increased. Vit. A levels in the plasma and liver of the calves suckling cows on adequate and inadequate levels of vit. A precursors were closely associated with the carotene intake during lactation, but were also influenced by the liver stores of the cow at parturition.