Effect of black soldier fly (Hermetia illucens) meal inclusion on growth parameters, somatic indexes and fillet yield of pikeperch (Sander lucioperca).

Introduction. In order to fully replace the natural diet with formulated feed, diets for pikeperch has to contain high levels of protein traditionally covered by fishmeal (FM). Nevertheless, FM sources are not endless and thus price is trailing on the market, thus starting to be unfavorable for commercial fish farming [1]. The main objective of this study was to evaluate the effects of different dietary insect meal (IM) inclusion levels on growth performances, somatic indexes and fillet yield of pikeperch. Animals, material and methods. In all, 600 pikeperch juveniles (initial body weight were 68.7 ± 7.1 g) were randomly distributed into twelve 170 L round plastic tanks with conical bottom. Thirty of fifty fish in each tank were individually tagged using PIT transponders (Loligo Systems, Denmark). Four experimental diets were formulated to be isonitrogenous, isolipidic and isoenergetic: a FM-based diet was used as control (CO), and three diets where a partially defatted black soldier Hermetia illucens larvae meal (BSF) substituted 25% (H25), 50% (H50) and 100% (H100) of FM. At the end of a 84 days growing trial, 20 fish from each group were killed by over anesthesia and dissected. Organs were removed for calculation of hepatosomatic and index of perivisceral fat. Simultaneously, 33 fish from each group were filleted by one experienced person to evaluate fillet yield. All data were analyses using one-way ANOVA and differences were considered significant at p<0.05. Results and discussion. At the end of the trial, pikeperch fed with H100 diet significantly reduced growth and other performance parameters. Groups H25 and H50 showed similar growth rate as CO (Table 1). Hepatosomatic and perivisceral fat index were decreased in fish fed H50 diets. Conclusion. Results of this study indicated that a partially defatted BSF meal can be used up to 50% of FM substitution in practical diets for pikeperch without effect on growth rate, feed conversion ratio and fillet yield. The 100% of FM substitution negatively affected fish performance, feed conversion ratio and fillet yield. References: [1] Renna et al. (2017) J. Anim. Sci. Biotechnol. 8, 57.