Effects of black soldier fly (Hermetia illucens) larvae meal protein as a fishmeal replacement on the growth and immune index of yellow catfish (Pelteobagrus fulvidraco)

A 65 days feeding trial was conducted to evaluate the potential of black soldier fly larvae (BSFL) as a fish meal (FM) protein alternative in the diet of yellow catfish. Fish meal protein was replaced with BSFL meal protein at 0% (control), 13%, 25%, 37%, 48%, 68%, 85% and 100%. Compared with the control group, increased growth performances (e.g. weight gain rate increased by 21.7%) and immune indexes (e.g. serum lysozyme activity increased by 6.8%) of yellow catfish fed with diets in which a maximum of 48% FM protein was replaced by BSFL meal protein was determined. The diet in which 25% FM protein was replaced by BSFL meal protein resulted in the greatest growth performances (e.g. weight gain rate increased by 29.1%) and immune indexes (e.g. serum lysozyme activity increased by 31.9%) as well as the lowest feed conversion ratio (0.9) among all diets tested. No significant differences in survival rate, body indexes or composition were determined among all treatments. Therefore, BSFL meal protein has the potential to partially replace FM protein in the diet of yellow catfish, and it may also enhance the immunocompetence of the fish.