The Placental Transmission and Fetal Storage of Vitamin A and Carotene in the Bovine

The literature records several references (1, 3, 5, 7) that state there is little or no reserve of vitamin A in the newborn calf. However, it is known that a lack of vitamin A or its precursor, carotene, in the pregnant cow's diet may result in a stillborn, blind, or weak calf. Obviously, a sufficiency of this vitamin must traverse the placental barrier to provide for the normal fetal development: However, the factors involved in the placental transmission and fetal storage of vitamin A have not been explored. The results of Braun and Carle (2), although complicated by pathological conditions, suggest that the vitamin A content of the bovine fetal liver may be influenced by the maternal diet.