The growth performance, body composition and nonspecific immunity of Tilapia (Oreochromis niloticus) affected by chitosan

The aim of this study was to investigate the effects of dietary chitosan on the growth performance, body composition and non-specific immunity of tilapia (Oreochromis niloticus). Chitosan were added to the basic diet to formulate five kinds of test feeds (0, 2, 4, 6 and 8 g kg(-1)). The diets containing 4 g kg(-1) chitosan increased body weight gain, feed conversion rate, specific growth rate, body protein, superoxide dismutase activity, catalase activity, lysozyme, disease resistance ability against Aeromonas hydrophila and decreased hepatopancrease lipid levels, plasma total cholesterol, plasma triacylglycerol, aspartate aminotransferase and alanine aminotransferase of tilapias compared with those of the control group. However, a high level of chitosan (8 g kg(-1)) decreased its efficiency compared to moderate level of chitosan (4 g kg(-1)). The results demonstrated that chitosan could promote the growth of tilapias and improve their disease resistance against A. hydrophila.