The Minimum Requirement of Young Pigs for a Purified Source of Carotene

Abstract
The minimum requirements of young pigs, which were depleted of their vitamin A reserves, for purified carotene (80–85 percent beta carotene) in cottonseed oil are reported. Criteria used were blood plasma and liver concentrations of vitamin A, cerebrospinal fluid pressures, nightblindness, and rates of gain. To restore initial blood plasma vitamin A levels and provide some liver storage of vitamin A, 25 micrograms of purified carotene per kilogram body weight was shown to be the minimum daily requirement. The feeding of 17.5 micrograms per kilogram body weight daily did not permit liver storage of vitamin A but was sufficient to restore initial plasma vitamin A levels under the environmental conditions of experiment 2. Ten micrograms of purified carotene per kg. body weight daily was sufficient to overcome gross deficiency symptoms and to promote good average daily weight gains. Copyright © . .