Abstract:

300 tilapias were used to investigate the effects of different level of dietary Cd on growth, digestive enzyme activities of tilapia intestinal tract, which were divided into five groups with four replicates in each group and exposed to dietary Cd at concentrations of 0, 50, 100, 200, 400 mg/kg for 8 weeks. Compared with the control group, the weight gain rate and specific growth rate were both decreased significantly in 200, 400 mg/kg Cd group (P<0.05); No significant difference in the feed rate, feed conversion rate and survival rate were found among all groups(P>0.05); The activities of amylase and protease in intestinal tract were decreased significantly when the level of dietary Cd was 50 mg/kg (P<0.05), the activity of lipase in intestinal tract was decreased significantly only in 400 mg/kg Cd group (P<0.05). It suggested that tilapia had strong tolerance to dietary Cd, the weight gain rate and specific growth rate could be restrained significantly in 200 mg/kg Cd group. And the activities of amylase and protease were decreased in 50 mg/kg group significantly, the activity of lipase decreased only in 400 mg/kg group.