Effect of dietary lipid levels on growth, survival and serum metabolites of snow trout (Schizothorax zarudnyi) fingerlings

The present study was carried out to evaluate the effect of dietary lipid levels on growth performance¡ body composition¡ feed efficiency and blood metabolites of snow trout (Schizothorax zarudnyi) fingerlings. Ninety-six fish averaging 5.46±0.85 g were randomly distributed into 12 of 30 L aquariums (8 fish/aquarium). Triplicate groups of fish were fed for 56 days four isonitrogenous experimental diets (34.5% crude protein) comprising 1601-2026.1 kj digestible energy g-1¡ containing 5¡ 8¡ 12 or 15.5% crude lipids. There were significant differences in body weight increase¡ feed efficiency¡ protein efficiency¡ food conversion ratio and specific growth rate (P0.05). Whole body lipid significantly increased in fish fed 15.5% lipid diets than fish fed 5¡ 8¡ 12 and 15.5% lipid¡ but there was no significant difference in protein¡ ash and moisture. Among serum metabolites¡ only triglyseride showed significant differences among the four dietary lipid levels and in 5% diet was lower than others. In conclusion¡ diets with 5-8% lipid are able to provide suitable level of lipid for snow trout fingerlings.