Alterations on growth performance, antioxidant responses and lipid metabolism in liver for juvenile hybrid grouper (♀ Epinephelus fuscoguttatus x ♂ Epinephelus lanceolatus) fed dietary vitamin E

The theme of present study was to estimate the alterations on growth performance, antioxidant responses and lipid metabolism in liver of juvenile hybrid grouper (female Epinephelus fuscoguttatus x male Epinephelus lanceolatus) fed dietary vitamin E (VE). The 540 fish (initial weight 8.79 +/- 0.06 g) were distributed into 18 fiberglass tanks and fed isonitrogenous and isolipidic diets with VE at different levels (11, 43, 98, 193, 404, and 789 mg/kg) for 7 weeks. Results showed that weight gain rate (WGR), specific growth rate, protein efficiency ratio, and condition factor were significantly improved in fish fed dietary VE levels. The triglyceride levels in serum, and the number and size of lipid droplets and the content of malondialdehyde in the liver of the treatment groups significantly decreased. In addition, dietary VE improved the activities of hepatic antioxidant (catalase (CAT), superoxide dismutase, and total antioxidant capacity) and lipid metabolism enzymes (hormone sensitive lipase (HSL)) and regulated the expressions of antioxidant (CAT, hepatic copper/zinc superoxide dismutase, and nuclear factor erythroid-2-related factor 2) and lipid metabolism related genes (HSL, fatty acid synthase, lipoprotein lipase, peroxisome proliferator activated receptor-gamma and carnitine palmitoyl transferase-1). The appropriate VE supplementation was assessed at 133.45 mg/kg according to the WGR broken line analysis model. Overall, dietary VE could enhance the antioxidant capacity and reduce the hepatic lipid deposition of hybrid grouper, thereby improving its growth performance.