Complete Substitution of fish meal with black soldier flies Hermetia illucens (L. 1758) larvae meal at varying incorporation rates for feeding Oreochromis niloticus raised in captivity

Background Black soldier fly larvae are exceptional ingredients, often used to replace fish meal. They can be easily cultured using waste and by-products. This study assesses the effect of black soldier fly larvae (BSFL) meal on the growth of Oreochromis niloticus raised in captivity, as well as the economic impact of replacing fish meal with BSFL meal in its diet. Method Black soldier fly larvae (BSFL) were produced for 15 days after egg hatching. The substrate of BSFL production was Soy bran obtained by processing soy cheese. Five different treatments were applied, with TR (imported feed); T0 (diet with 0% incorporation of black soldier fly larvae meal); T40; T50 and T60 are diets with 40%, 50% and 60% incorporation of black soldier fly larvae meal. The feeding frequency was 4 times/day. Each treatment was tested in triplicate for 28 days. Results The specific growth rate obtained during the experiment varied significantly (P < 0.05) with the treatments from 2.88 ± 0.09 to 4.50 ± 0.12%/day. The feed conversion rate (FCR), ranged from 2.25 ± 0.05 (T40) to 1.08 ± 0.04 (T60). The protein efficiency ratio (PER) showed a significant difference (P < 0.05) with the treatment. It ranged from 0.81 ± 0.07 (T40) to 2.34 ± 0.06 (TR). The survival rates varied from (T0) (92.66 ± 3.52) to (T50) (100.00 ± 0.00). The economic conversion ratio (ECR) presented a significant difference (P < 0.05). The best ECR was obtained with T60 (1.62 ± 0.09) and T50 (2.42 ± 0.17). Based on the parameters studied, 40%, 50%, and 60% of BSFL meals showed better performance compared to fish meal. The cost production analyses were used to evaluate the economic impact of utilizing BSFL meal instead of fish meal in O. niloticus feeding. Conclusion It is recommended to use 50% and 60% substitution rates for better economic profitability.