Effect of dietary replacement of fish meal protein with crawfish shell meal ( Procambarus clarkii ) on the growth performance, digestive enzyme activity and anti‐oxidative capacity of Oujiang color common carp ( Cyprinus carpio var. color )

Abstract

This study was designed to evaluate the effects of dietary crawfish shell meal (CSM) on the growth performance, digestive enzyme activity and anti-oxidative capacity of Oujiang color common carp. 180 juvenile fish (initial weight 3.0 ± 0.5 g) were assigned to the control group and the CSM25 group (fed with 25% substitution of fish meal by CSM) for 8 weeks. Results showed that significant improvement in the weight gain rate (WGR) in CSM25 group than the control (p < .05), whereas no significant change in feed conversion ratio, specific growth rate and feeding intake between the groups (p > .05). Also, no significant difference was obsevered between the groups in terms of serum biochemical index and muscle composition (p > .05). And liver superoxide dismutase, catalase, glutathione peroxidase (GPx), lysozyme (LYZ) and protease activities in CSM25 group were significantly higher (p < .05). Moreover, histological analysis indicated that width of mucosa and thickness of muscular coat in mid-intestine were significantly changed (p < .05). In conclusion, dietary supplement with CSM25 induced high oxidative stress, promote protease activities and had no negative effects on the growth performance of Oujiang color common carp. Hence, CSM may be a viable alternative protein source to reduce the demand for fish meal.