A study of effects using three additives on growth performance, digestive enzymes and the activity of the immune-related enzymes of the juveniles common carp

Abstract:

In order to explore whether it is feasible for Bacillus subtilis to replace antibiotics to be applied in juvenile common carp feed, an 8 week feeding trial was under conducted with adding Flavomycin(4 mg/kg)(G1), Quinocetone(125 mg/kg)(G2) and Bacillus subtilis(300 mg/kg)(G3) to feed initial body weight of (24.39±0.30)g. The results showed that, compared with the control group, Bacillus subtilis had great promotion on growth performance and digestive enzymes activity, besides, it can also improved the LSZ activity and reduced the GOT and GPT activity(P<0.05). But the two antibiotics groups all had no function in promoting growth performance(P>0.05), whereas, the Flavomycin group can increase the activity of protease and lipase of hindgut and amylase of hepatopancreas(P<0.05),and the Quinocetone group had no funcition in this aspect(P>0.05). What's more, the two groups adding antibiotics both can increase the LSZ activity(P<0.05), and the Flavomycin can reduce the GOT and GPT activity significantly(P<0.05), and the SOD activity was extraordinarily higher in Quinocetone group(P<0.05). Besides, compared with the antibiotics groups, we can find that the amylase and lipase activities of hindgut of Bacillus subtilis group were super higher than the Flavomycin group(P<0.05), and it had better promoting digestion ability than Quinocetone. Whatever , the SOD and AKP were greatly higher than Flavomycin(P<0.05),and the GOT and GPT activities were significantly decreased than Quinocetone group(P<0.05). So we can conclude that Bacillus subtilis had better function on promoting growth performance , increasing digest enzyme activity, and it also significantlty influenced the immune serum enzymes activity. So we can use Bacillus subtilis to replace these two kinds of antibiotics to be applied in juvenile common carp feed.