Substituting fishmeal with extruded soybean meal in diets did not affect the growth performance, hepatic enzyme activities, but hypoxia tolerance of Dolly Varden (Salvelinus malma) juveniles

摘要: Extruded soybean meal (ESBM) showed increased digestibility of crude protein, amino acids and fat, better oil retention capacities, attenuated anti‐nutrient factor effects improved its nutritive value compared with raw meal, indicating a promising application prospects for ESBM in fish culture. This study aimed to evaluate the substituting fishmeal on growth performance, hepatic antioxidant capacity resistance hypoxia stress juvenile Dolly Varden (Salvelinus malma). Five hundred forty were randomly assigned six groups fed iso‐nitrogenous iso‐energetic diets replacement 0% (control), 10% (G1), 20% (G2), 30% (G3), 40% (G4) 50% (G5) fishmeal. After an 81‐day feeding trial, substituted (G2 G5) no significant differences survival rates, final body weights, weight gain feed conversion ratios, specific hepatosomatic indexes condition factors control group (G0), reflecting normal food intake performance. The enzyme activities total capacity, catalase superoxide dismutase not affected by diets, showing harmful ROS eliminating abilities. Hepatic HSP70 expression levels had 1.3 times G5 group, less tolerance high level ESBM. In conclusion, replacing, despite 50%, detrimental performance activities, but lowering