Comparative role of vitamin A and beta-carotene on reproduction and neonate survival in rats.
Female rats were used to investigate the comparative role of vitamin A and beta-carotene (dietary or injected) on growth, feed intake and reproduction. After 3 wk of vitamin A and beta-carotene depletion, rats were assigned to one of six groups: 1) CON = fed 5% NRC recommended level of vitamin A (= 60 mug retinol equivalent (RE)/kg diet); 2) VA = fed 100% of vitamin A (= 1200 mug RE/kg diet); 3) HVA = fed 150% of vitamin A; 4) VA+C = fed 100% of vitamin A + 1.2mg beta-carotene; 5) VA+IC = fed 100% of vitamin A + injected weekly with 8.37 mg of beta-carotene; and 6) VA+IVA = fed 100% of vitamin A + injected weekly with 1400 IU of vitamin A. The level of vitamin A and beta-carotene in dam blood and liver reflected the level of supplementation. No difference in feed intake or body weight was observed. Although mean litter size was similar for all groups, mean pup weight at birth was lowest for deficient rats. Pup mortality through 2 wk postpartum was lower for groups receiving higher levels of either vitamin A or beta-carotene. However, supplemental beta-carotene did not influence growth or reproductive performance. Therefore, low intakes in vitamin A or beta-carotene had no effect on feed intake, growth or reproduction in female rats but decreased fetal growth and increased mortality among pups.
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Department of Animal Sciences Washington State University, Pullman, WA 99164-6320 USA.
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