Effects of complete enzyme preparation on growth performance, serum biochemical and immune indices of juvenile yellow catfish (Peltobagrus fulvidraco)

We randomly assigned 360 juvenile yellow catfish (Peltobagrus fulvidraco)with average body weight 2.48 g to 4 groups, and fed the control(G0) with basal diet, the other 3 groups (G100,G200 and G400 ) with basal diet supplemented with 100 mgkg-1, 200 mgkg-1 and 400 mgkg-1 complete enzyme preparation (CEP), respectively. After feeding for 8 weeks,the weight gain rate (WGR), specific growth rate (SGR) and feed intake (FI) increased with the CEP concentration. Besides, the WGR, SGR and FI of G400 were higher than those of the control by 15.4%,7.5% and20.3%（P0.05）, respectively. No significant difference was found among all the treatments in body moisture, crude protein, crude lipid and ash content (P＞0.05). Serum urea content decreased with increasingCEP in diets, while glutamic-pyruvic transaminase (ALT), glutamic-oxalacetic transaminase (AST) activities and total protein（TP）content increased (P＞0.05). The activity of lysozyme（LSZ）increased and then decreased（P0.05）. In conclusion, thefeed added with 400 mgkg-1 CEP can promote the growth and ALT activities of yellow catfish, and decrease its urea content; thefeed added with 200 mgkg-1CEP can significantlyincrease the TP content and LSZ and AST activitiesof the fish.