Dietary lipid levels affect growth, feed utilization, lipid deposition, health status and digestive enzyme activities of juvenile Siberian sturgeon, Acipenser baerii

A 10‐week experiment was conducted to evaluate the effects of dietary lipid levels on growth, feed utilization, lipid deposition, health status and digestive enzyme activities of juvenile Siberian sturgeon (Acipenser baerii). Six isonitrogenous diets were formulated with lipid levels at 51.1 (L5), 88.7 (L9), 129.6 (L13), 169.3 (L17), 208.4 (L21) and 248.8 g/kg (L25). The sturgeons fed with L17 had the highest growth and feed utilization. Higher dietary lipid obtained significantly lower PPV than that of L17 (p < .05). Based on WGR, PPV, the optimal dietary lipid was estimated at 169.9, 176.0 g/kg. The lipid deposition in the whole body, muscle and liver enhanced significantly as the dietary lipid increased (p < .05). Dietary lipid levels affected serum biochemical parameters, with the highest AST, TC, LDL‐C and LDL‐C/TC in L21 or L25 group and highest HDL‐C in the L17 group. Serum antioxidants, oxidants and liver MDA content maintained upward trends with increasing dietary lipid from 51.1 to 248.8 g/kg (p < .05). Lipase activity in the spiral valve intestine increased when dietary lipid rose from 51.1 to 169.3 g/kg, but declined when lipid level up to 208.4 and 248.8 g/kg (p > .05). To sum up, the optimal dietary lipid was 169.9–176.0 g/kg for juvenile Acipenser baerii.