Comparison of Digestive Enzyme Activity in Different Age of Ancherythroculter nigrocauda

Activities of protease,amylase and lipase from hepatopancreas and gut of 1 year old and 2 years old Ancherythroculter nigrocauda were analyzed by using biochemical technique,and the three digestive enzyme activities of the two groups were also compared.Results showed that activities of protease in different digestive parts of 1 year old fish ranged as follows:foregutmidguthindguthepatopancreas,whereas in 2 years old fish activities of protease were midgutforeguthindguthepatopancreas.The amylase activities were hepatopancreasmidgut hindgutforegut in both 1 year old and 2 years old fish.Also,the lipase activities of both groups were hindgutmidgutforegut hepatopancreas.In total,the digestive enzyme activities of 1 year old fish were higher than those of 2 years old fish.The protease and amylase activities in the two groups had significant differences,whereas the lipase activities in the two groups had no significant differences.The results indicated that content of protein and carbohydrate should be reduced properly in artificial diets of 2 years old A.nigrocauda.