Effect Of Virginamycin Supplement On The Growth Performance Of Ictalurus Punctatus

Five practical groups were designed,one control group and four experimental groups supplied with different levels of virginamycin.Each group contained three parallelisms.A feeding trial was conducted to find out the differences between control group and virginamycin group in physiological function and some non-specific immune indices such as lysozyme(LSZ)activity, superoxide dismutas (SOD)activity,transaminase activity in hepatopancreas and hemoglobin content of blood in order to evaluate the influence of adding virginamycin to the feed of Ictalurus punctatus.The feeding trial lasted for eighty days.There were great differences in special growth ratio and feeding efficiency between control group and virginamycin groups.Compared with the control group,the special growth ratio of the levels of virginamycin 20 mg/㎏,40 mg/㎏,60 mg/㎏ groups increased by 4.18%,5.87%,7.32%,respectively. However,the special growth ratio of virginamycin group fed with the level of 80mg/kg decreased by 1.47% compared with the control group.Under the level of 60mg/kg,the special growth ratio represented significant positively correlation with the increasing inclusion of virginamycin(R=0.964).However, the special growth ratio decreased when fish were fed with a combination of 80mg/kg virginamycin.Feed conversion rate decreased by 6.85%,7.13%,9.85% respectively when fish was fed with the diet containing 20 mg/㎏,40 mg/㎏,60 mg/㎏ virginamycin. But feed conversion rate of level 80mg/kg group was 3.53% more than the control group.Under the level of 60mg/kg, the feed conversion rate represented negatively correlation with the increasing inclusion of virginamycin (R=-0.917). Feed conversion rate of level of 80mg/kg decreasedThe combination of virginamycin in feed had some effects on body/length,bowel/body and hepatopancreas/body.Body/length of virginamycin groups was higher than control group.And the bowel/body of virginamycin groups was lower than control group. Hepatopancreas/body of level 20mg/kg,80mg/kg were higher than control group,and the level of 40mg/kg,60mg/kg groups were lower than control group.The glutamic oxaloacetate transaminase (GOT) activities in serum of virginamycin groups were not higher than control group,However, transaminase activity in hepatopancreas was not different significantly.In hepatopancreas, the superoxide dismutas (SOD) activities of four experimental groups were not higher than control group.In mucus of skin ,SOD activity was higher than control group except level of 60mg/kg,and the LSZactivities were higher than control group except level of 80mg/kg.In serum,LSZ ctivities of four experimental groups were lower than control group.The content of hemoglobin in blood of virginamycin groups were higher than control group except 20mg/kg group.The tryosinase activities in serum of four virginamycin groups were lower than control group.In backside skin,the tryosinase activities of 40mg/kg,60mg/kg groups were higher than control group.In belly skin, the results were also higher than control group.