Abstract:In order to decrease dietary fish meal content and culture cost, this experiment was conducted to investigate effects of fish meal replacement by soybean meal on growth performance, body composition, digestive enzyme activities and hepatic biochemical indexes of bullfrog, Rana (Lithobates) catesbeiana. The basal diet contained 300 g/kg fish meal, then fish meal of basal diet was replaced with 0%, 20%, 40%, 60%, 80% and 100% soybean meal to formulate six iso-nitrogenous and iso-energetic diets (D1, D2, D3, D4, D5 and D6, respectively). Bullfrogs were fed with six experimental diets for 60 days. The results showed that no significant differences in feeding rate (FR), survival rate (SR), hepatic somatic index (HSI), viscera somatic index (VSI) and hepatic malondialdehyde (MDA) were found among all treatments. Weight gain rate (WGR), specific growth rate (SGR), protein efficiency ratio (PER) and protein productive value (PPV) of bullfrogs fed with no-fish-meal diet (D6) were significantly lower than those of other groups, while the opposite is true for feed conversion ratio (FCR). Condition factor (CF) and hind leg index (HLI) significantly decreased as the dietary soybean meal increased. No-fish-meal group has the lowest CF among all treatments. Proteases activity in intestine significantly declined as dietary soybean meal level increased, while amylase and lipase activities were just opposite. Fish meal replacement by soybean meal had significant effects on hepatic superoxide dismutase (SOD) and catalases activity (CAT). SOD activity was the lowest in bullfrogs fed D5 diet. While, CAT activity was the lowest in bullfrogs fed D6 diet. Based on these results, we suggest that 60%-80% fish meal could be replaced by soybean meal in practical diets of bullfrog.