Effects Of Dietary Vitamin E Suppleme Ntation On Growth,immunity And Stress Resistance Of Epinehelus Moara

The paper is about the influences of VE on growth, VE in tissue(liver, muscle and serum) and immune response(Ig M activity and lysozyme) of Epinehelus moara. The content of vitamin E in 5 diets is 11.09 mg/kg、47.52 mg/kg、91.38 mg/kg、134.57 mg/kg、178.92 mg/kg respectively. Epinehelus moara was fed to 15 floating netcages(1 m ′ 1 m ′ 0.8 m) with 20 fish(initial long 9.3 cm, initial weight 15.58 g) each twice daily(09:30 AM,16:30 PM). Results indicate that VE is important on growth of Epinehelus moara from 11.09 mg/kg to 91.38 mg/kg. From 91.38 mg/kg to 178.92 mg/kg, the weight gain rate increased was not significant. From 11.09 to 91.38 mg/kg, the VE concentration in liver, serum and muscle increased was significant, but not significant from 91.38 to 178.92 mg/kg. The VE was crucial to lysozyme and Ig M activity of Epinehelus moara in serum and the Epinehelus moara had the maximal level of lysozyme activity and Ig M activity when fed 134.57 and 91.38 mg/kg respectively. In summary, the VE for growth and immune in Epinehelus moara was about from 139.68 to 149.59 mg/kg.Then this study was about the effect of VE supplementation on Epinephelus Moara juveniles under ammonia nitrogen stress. Five diets were formulated to contain 0, 35, 80, 125 and 170 mg/kg of VE. After 56 days of feeding, all fish were exposed to ammonia nitrogen for 6 h, and then the blood glucose, lactate, cortisol, superoxide dismutase(SOD), catalase(CAT), malondialdehyde(MDA), glutathione peroxidase(GSH-Px), total antioxidant capacity(T-AOC) were measured. The results showed that the blood concentrations decreased with incremental dietary VE levels, while this difference was not significant. The lactate concentrations showed stable in 47.52 mg/kg VE treatment. When the VE level was higher than 47.52 mg/kg, the serum SOD activity was not affected by the ammonia nitrogen after 56 days of feeding. The CAT activity was not significant when the VE concentration was more than 91.38 mg/kg neither after feeding or stress. The MDA contents showed a ris ing trend in fish fed diets containing low doses of VE after feeding and stress, and no significant difference was observed in fish fed high doses of VE. The GSH-Px activities increased significantly on high level of VE treatments. The T-AOC concentrations decreased in low level of VE treatments after feeding and stress; however, the T-AOC contents increased in fish fed more than 47.52 mg/kg VE, and then decreased after ammonia nitrogen stress. In a word, the VE is crucil to the anti-stress of Epinephelus Moara; ingestion of a basal diet supplemented with more than 91.38 mg/kg VE could enhance res istance against ammonia nitrogen stress.Last for the research to effects of dietary VE on tolerance of Epinehelus moara for low salinity stress, five levels of VE supplementation had been design as 11.09、47.52、91.38、134.57 and 178.92mg/kg in this experiment. Juvenile E. moara had been fed for 56 days, and the real supplementation of VE was tested. Then, low salinity(12) stress experiment was last for 6h, different indexes of experimental fish were tested, serum biochemical indexes: COR, GLU, LD; SOD, CAT, GSH-Px T-AOC and MDA; as well as gill Na+/K+-ATPase(NKA), Ca2+-ATPase activities. The result present that serum COR concentration was increased by supplementing VE in diet. And after low salinity stress, serum COR concentration in every groups increased. There were not huge different among serum GLU concentration in different groups. And after low salinity stress, serum GLU concentration in group A, B, C increased significantly. Serum LD concentration in group C, D, E increased in feeding experiment, then it increased in group A, B and decreased in group C, D, E after low salinity stress. The result of serum COR, GLU, and LD suggested that supplementation of VE wo uld enhance anti-stress ability of E. moara, and the best range of supplementation of VE was 47.52-134.57mg/kg. The supplementation of VE were close relative to serum SOD, CAT, and GSH-Px activities, T-AOC, MDA concentration, of which range was 91.38-178.92 mg/kg that could strengthen antioxidant function of E. moara. VE can enhance the NKA activity. When the supplementation of VE was 91.38mg/kg, low salinity stress had little effect on NKA activity. The range of supplementary VE which was 91.38-178.92 mg/kg, appeared to result in the activation of the Ca2+-ATPase activity. This study suggested that diets supplemented with VE can enhance vitality and anti-stress ability of body. In summary, analys is of biochemical, antioxidant and ion-regulatory indicators estimate that the best range of supplementation of VE was 91.38-134.57mg/kg.