Influence of dietary black soldier fly (Hermetia illucens Linnaeus) pulp on growth performance, antioxidant capacity and intestinal health of juvenile mirror carp (Cyprinus carpio var. specularis)

This study was conducted to investigate whether dietary supplementation of black soldier fly (Hermetia illucens Linnaeus) pulp (BSFP) affects growth performance, antioxidant capacity and intestinal health of juvenile mirror carp (Cyprinus carpio var. specularis). A total of 270 juvenile mirror carp (13.68 +/- 0.02 g) were randomly allotted to five dietary treatments, BSFP0, BSFP25, BSFP50, BSFP75 and BSFP100, in which BSFP was included in the basal diet at 0, 43.7, 87.3, 131 and 174.7 g/kg, respectively. Then, fish were fed to apparent satiation for 8 weeks. Fish growth performance and nutrient utilization were not different among the five groups (p > .05). Increasing BSFP dietary content significantly decreased whole-body lipid content but increased kidney index (p < .05). The general relative intestine length was significantly higher in the BSFP100 group than the BSFP0 group (p < .05). Increasing BSFP dietary content significantly increased serum catalase activity and decreased malonaldehyde content (p < .05). The intestinal villus height, villus area and muscle layer thickness were significantly lower in the BSFP100 group than the BSFP0 group (p < .05). No significant differences in the activity of intestinal trypsin, lipase and amylase were observed among all groups (p > .05). In conclusion, this study indicated that BSFP at the level below 131 g/kg could be added in diet of juvenile mirror carp without any negative effect on growth performance and intestinal health. Dietary BSFP inclusion at low levels decreased the whole-body lipid content and increased the antioxidant activity of juvenile mirror carp.