Effects of exogenous multienzyme complex supplementation in diets on growth performance, digestive enzyme activity and non-specific immunity of the Japanese seabass, Lateolabrax japonicus

摘要

This experiment aimed to investigate the effects of exogenous multienzyme complex (EC) on growth performance, digestive enzyme activity and non-specific immunity of the Japanese seabass, Lateolabrax japonicus (initial weight 27.09 +/- 0.08 g). EC includes protease, xylanase, glucanase and mannase. Japanese seabass were given six levels of EC (0, 0.5, 1.0, 1.5, 2.0 and 2.5 g/kg) for 28 days. Results show that EC significantly enhanced the weight gain rate and specific growth rate (p < .05), while the feed conversion ratio reduced significantly (p < .05). Activities of lipase and trypsin in liver and intestine significantly increased (p < .05). Alkaline phosphatase, superoxide dismutase and lysozyme activities in serum and liver significantly increased (p < .05), while the content of malondialdehyde in liver significantly declined (p < .05). Regression analysis showed that the optimal supplementation of EC in WGR, SGR, FCR, SOD and LZM activity in serum was 1.66, 1.67, 1.81, 1.71 and 1.53 g/kg, respectively, while the best SOD, LZM activity in liver, trypsin activity in liver and intestine supplement were 1.64, 1.51, 1.81 and 1.97 g/kg. In conclusion, EC supplemented can improve the growth performance, digestive enzyme activity and non-specific immunity of Japanese seabass, and it is recommended that the optimal supplementation of EC in diets of Japanese seabass is 1.5-2.0 g/kg.