Vitamin A Requirement of the Gestating and Lactating Sow

Abstract

Forty-eight sows were allotted to six levels of vitamin A to evaluate the requirement of the gestating and lactating sow. Stabilized vitamin A palmitate was added to a basic diet, which was calculated to be nearly devoid of natural sources of carotene or vitamin A, to provide levels of vitamin A ranging from none to 23,510 I.U./kg. of total diet. The sows were maintained on the treatments throughout two gestation and lactation periods. Criteria used in evaluating the adequacy of the various treatments of vitamin A were: number and weight of pigs; levels of vitamin A in plasma, liver and milk; cerebrospinal fluid pressures and any gross signs of abnormality. The level of vitamin A which the dams received had no apparent effect upon number or weight of pigs at farrowing or at 14 days of age. Levels of plasma vitamin A from either sows or pigs were too variable to be considered a measure of the vitamin A status of the animals. Statistically significant increases of vitamin A in colostrum and 14-day milk from sows, as well as in pig livers, were obtained by feeding the higher levels of vitamin A.