Effects of dietary lipid levels on growth, intestinal digestive enzyme and main lipid metabolic enzyme activities of Sebastiscus marmoratus

We evaluated the effects of dietary lipid levels on thegrowth, intestinal digestive enzyme and main lipid metabolism enzyme activities of Sebastiscus marmoratus. Two hundred and twenty-five juveniles with average initial body weight of (27.560.19) g were randomly divided into 5 groups fed with diets at lipid levels of 6.1%, 9.5%, 12.4%, 15.1% and 18.5%, respectively. The experiment lasted for 60 d and the results show that: 1) The specific growth rate (SGR) and condition factor (CF) first increased then decreased and reached the maximum values in diet C (12.4%) (P0.05), while the feed conversion rate (FCR) showed a contrary trend. The hepatosomatic index (HIS) increased with increasing dietary lipid level (P0.05). No significant difference was found in thesurvival among all diets; 2) The lipase activity of intestinal tract increased with increasing dietary lipid level (P0.05). No significant difference was found in the pepsin and amylase activities among all diets; 3) The fatty acid synthetase activity first increased then decreased from 6.1% to 18.5% (P0.05). The activities of lipoprotein lipase and hepatic lipase increased but no significant difference was found among all diets. According to the regression curve of SGR and dietary lipid level, the suitable dietary lipid level for S.marmoratus should be 12.72%.