Effects of zymolytic black soldier fly (Hermetia illucens) on the growth, antioxidant capacity, and immunity of Yellow River carp (Cyprinus carpio)

Summary

This study evaluated the potential of the zymolytic black soldier fly (Hermetia illucens, ZBSF) as feed for Yellow River carp (Cyprinus carpio). Six diets, including a normal protein diet (C) and five reduced-protein diets with different ZBSF levels (R, RZ5, RZ10, RZ15, and RZ20), were fed to 630 fish with an average weight of 5.11 ± 0.02 g for 8 weeks. Dietary ZBSF did not affect fish growth in any of the R groups. The hepatopancreatic crude protein, DHA, and n-3 PUFA levels in the RZ15 and RZ20 groups were lower than those in the R group. Notably, compared to the R group, the RZ15 group showed significantly higher catalase activity in the serum and hepatopancreas, along with a significantly lower malondialdehyde content. The RZ15 group exhibited improved morphological health of the hepatopancreas and intestine. Furthermore, the expression levels of pro-inflammatory factors (il-6 and il-1β) in the hepatopancreas were significantly decreased and the expression levels of anti-inflammatory factors (il-10) were increased in the RZ15 group compared to the R group. The RZ10 and RZ15 groups showed decreased il-6 and tnf-α1 expression levels, but increased il-10 levels in the kidney. The RZ15 group showed significantly increased expression levels of antioxidant genes (nrf2, sod, cat, gpx1) in the intestine. The RZ15 group showed reduced cumulative mortality when the Yellow River carp were infected with Aeromonas hydrophila. Overall, the incorporation of 15 g/kg ZBSF into reduced-protein diets improved tissue health, antioxidant capacity, and immune function in Yellow River carp. However, it also decreased hepatopancreatic nutritional composition (crude protein and n-3 PUFA levels), highlighting a potential trade-off between physiological health benefits and nutritional quality.

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DOI : doi.org/10.1016/j.anifeedsci.2...
NVA : hdl.handle.net/11250/5556065