The Effect of the Prepartum Diet of the Cow on the Vitamin A Reserves of Her Newborn Offspring.
Feeding vitamin A at the rate of a million U.S.P. units daily to individual dairy cows in the latter stages of gestation augmented significantly the vitamin A concentration in the blood and the livers of their newborn calves, but pasture grazing, providing an abundance of carotene in the prepartum diet of the dams, failed to effect an increase over that observed in calves from dams restricted to a standard winter ration. The explanation for these divergent results is obscure, but it is suggested that the placental membrane may be more permeable to the ester form of vitamin A than to the alcohol form. This high initial vitamin A reserve in the newborn calf should have practical value in the maintenance of its postnatal health.
Wise
G H
GH
Caldwell
M J
MJ
Hughes
J S
JS