Effects of β-conglycinin on growth performance, antioxidant capacity and intestinal health in juvenile golden crucian carp, Carassius auratus

The objective of this study was conducted to research the effects of beta-conglycinin in the diets on the growth performance, immunity function, antioxidant capacity and intestinal health of juvenile golden crucian carp (Carassius auratus). Five diets contained respectively (0, 20, 40, 60 and 80 g/kg) beta-conglycinin, and were used to feed juvenile golden crucian carp for 56 days. Final weight, weight gain and specific growth rate were significantly reduced by dietary beta-conglycinin (20-80 g/kg). Feed efficiency and protein efficiency were significantly reduced by dietary beta-conglycinin (40-80 g/kg). In hepatopancreas, the activities of T-SOD, ACP, ALT and T-AOC were significantly suppressed by dietary beta-conglycinin (20-80 g/kg). The activities of LZM, AKP, CAT and GPx were significantly reduced by dietary beta-conglycinin (40-80 g/kg). The activities of protease were significantly reduced and the content of MDA was significantly increased by dietary beta-conglycinin (60-80 g/kg). In proximal intestines, the activities of protease and CAT were significantly decreased by dietary beta-conglycinin (40-80 g/kg). In mid and distal intestines, the activities of protease and CAT were significantly inhibited by dietary beta-conglycinin (20-80 g/kg). In intestines, T-AOC and GPx were significantly declined by dietary beta-conglycinin (20-80 g/kg). In proximal and mid intestines, the content of MDA were significantly increased by dietary beta-conglycinin (40-80 g/kg). In distal intestines, the content of MDA was significantly increased by dietary beta-conglycinin (20-80 g/kg). The expression of IGF-I was significantly decreased and the expression of IL-1 beta and TNF-alpha was significantly increased by dietary beta-conglycinin (20-80 g/kg). The structural integrity of intestinal tissues were damaged by dietary beta-conglycinin (20-80 g/kg), the part of intestinal villus were shed, the part of epithelial cells were separated from lamina propria. Ultimately, these results suggested dietary beta-conglycinin should be <20 g/kg in formula feed of golden crucian carp.