Effect of Blue-green Algae Meal on Growth and Accumulation of Microcystins in gibel carp(Carassius auratus gibelio)

摘要

Six isonitrogenous(crude protein content 38%) and isoenergetic(gross energy content 17kJ g-1) diets were formulated to investigate the effects of inclusion of blue-green algae meal on gibel carp(Carassius auratus gibelio).In each diet,15% of the protein was supplied by fish meal,and the rest supplied by soybean meal and blue-green algae meal.BGAO was used as control and contained no blue-green algae meal,and the content of blue-green algae meal in BGA15,BGA30,BGA45,BGA60,BGA75 diets were 15,30,45,60 and 75%,respectively.Each diet was fed to 5 groups of gibel carp for 12 weeks in a flow-through system.Final body weight and specific growth rate(SGR) of fish fed the BGA60 diet was significantly(P<0.05) lower than that fed the control diet.Mortality of gibel carp increased significantly with increase in algae meal inclusion,but there was no significant difference between fish fed the BGA30,BGA40,BGA60 and BGA75 diets.Feed conversion efficiency decreased significantly with the increase in algae meal inclusion.Fish fed BGA75 diet showed highest feeding rate while there was no significant difference between the other groups.Apparent digestibility coefficient of dry matter,protein and energy decreased significantly with increasing algae meal inclusion in diets.Asparate aminotransferase activity in liver was not significantly different between groups.Liver alanine aminotransferase activity of fish fed BGA45,BGA60 and BGA75 diets was significantly lower than that fed the control diet(BGAO).Microsystins content in muscle,liver,gall bladder and spleen increased significantly increasing algae inclusion.