DIFFERENT ROLES FOR B-CAROTENE AND VITAMIN-A IN THE REPRODUCTION ON RABBITS

beta-carotene is thought to have a positive effect on reproduction ind ependent of its role as a vitamin A precursor. The effect of beta-caro tene related to vitamin A in rabbit fertility was examined in 2 indepe ndent experiments. All rabbits received sufficient dietary vitamin A. The first experiment (superovulation and embryo transfer) was designed to determine possible effects of beta-carotene sources (synthetic and natural) on embryo donors and recipients. In the second experiment (s uperovulation) the influence of beta-carotene (synthetic) on vitamin A status in the blood and on reproductive performance was studied. Ther e was no obvious effect of beta-carotene on the numerous traits measur ed. High levels of serum vitamin A in Experiment 2, however, were posi tively related to an improvement in reproduction (higher numbers of co rpora lutea, lower numbers of cysts, more oocytes, more embryos, more embryos suitable for injection). These data suggest that the previousl y described effects of beta-carotene are mainly based on the metabolis m of vitamin A.