Abstract:10-week feeding trial was conducted to investigate the effects of four diets containing different combinations of selenium and vitamin E on the growth performance, nonspecific immune responses of Japanese flounder Paralichthys olivaceus and disease resistance when challenged with Vibrio anguillarum. The fish were fed purified diets with supplemented vitamin E at 60 mg/kg (designated e) or 300 mg/kg (designated E) combination with selenium at 0 mg/kg (designated s) or 3 mg/kg (designated S). Each diet was fed to triplicate groups of flounder with initial body weight of 38.5±0.15 g. After the final weighing, 8 fish were randomly taken from each aquarium and injected with V.anguillarum. Mortality was recorded daily for 7 days and nonspecific immune parameters were monitored in the remaining fish. At the end of the experiment, weight gain and phagocytic activity in blood was significantly greater in those fish fed the s/E and S/E diets compared with those fed the s/e and S/E diets. Glutathione peroxidase activity in serum and liver were significantly higher in fish fed the S diets compared with those fed the s diets. High cumulative mortality was found in fish fed the s/e diet than other dietary groups. These results indicate that no synergistic effect of excessive dietary vitamin E and selenium on growth performance, nonspecific immune responses and disease resistance to V.anguillarum in Japanese flounder..
