Vitamin E requirement of Penaeus vannamei

Abstract

An 8-week feeding trial was conducted to determine the dietary vitamin E requirement of the white-legged shrimp, Penaeus vannamei, using semi-purified diets. Shrimp exhibited significantly increased weight gain when fed increasing levels of vitamin E from 0 to 100 mg/kg diet, whereas no significant difference in growth was observed for shrimp fed diets containing vitamin E from 100 to 600 mg/kg. The vitamin E requirement of shrimp based on growth and estimated by the method of broken-line regression was 99 mg/kg diet. There was no difference in survival. The present study also indicated that vitamin E was an effective antioxidant preventing ascorbic acid-stimulated lipid peroxidation in mitochondrial and microsomal membranes, oxidative spoilage of shrimp tail muscle during frozen storage (−60°C) and peroxidation of dietary lipid. Dietary vitamin E levels of approximately 25 and 100 mg/kg diet were found to be required for suppressing ascorbic acid-stimulated mitochondrial and microsomal membrane lipid peroxidation in shrimp hepatopancreas and muscle, respectively. The synthetic antioxidant, butylated hydroxytoluene (BHT), was an effective antioxidant in vitro by protecting dietary lipid from peroxidation, but it was less effective in tissue protection and exhibited no inhibitory effect on ascorbic acid-stimulated mitochondrial and microsomal membrane lipid peroxidation. However, growth reduction of shrimp resulting from vitamin E-deficiency could be prevented by supplementation of BHT at 0.02% of the dietary lipid content.