The effects of defatted black soldier fly larvae meals (ECBSFL and OSBSFL) as fish meal alternatives in the diet of Penaeus vannamei (Boone, 1931)

A 60-day feeding trial evaluated the effects of defatted black soldier fly larvae (BSFL) ( Hermetia illucens ) raised in environment controlled or open systems as fish meal (FM) replacers on whiteleg shrimp ( Penaeus vannamei ) juveniles in brackish water (9 ppt). Nine experimental diets (36% crude protein, 372.49 Kcal digestible energy/100 g feed) replaced the FM with graded levels of defatted meals of BSFL raised in an environment controlled system (ECBSFL) or an open system (OSBSFL) at 0% (control), 25%, 50%, 75%, or 100%. 1,080 juveniles (average. weight 2.0±0.25 g) were distributed into nine groups (triplicates, 40 shrimp per hapa) and fed four times daily. Shrimps fed on the ECBSFL 75% diet had the best final body weight (18.43±0.11 g), weight gain percentage (773.22±8.21), specific growth rate (3.61±0.017%/day) and feed conversion ratio (1.36±0.01) and no significant changes in whole-body composition and survival rate. Protease activity (units/min/mg protein) was higher in the ECBSFL 50% (3.11±0.19) and ECBSFL 75% (3.61±0.15) groups, while the control group had higher lipase activity (0.46±0.02 units/hour/mg protein). The ECBSFL 75% group showed higher hepatopancreatic AST (5.11±0.24) and ALT (2.99±0.28) activities (units/min/mg protein) and serum total protein (5.65±0.70 g/dl), while the OSBSFL 100% group had higher serum glucose (81.07±3.36 mg/dl) but lower cholesterol (87.23±2.26 mg/dl) and triglycerides (128.51±0.65 mg/dl). Based on these results, it can be concluded that up to 75% of fish meal can be replaced with meal of BSFL raised in an environment controlled system at the inclusion level of 18.75%, or up to 50% with meal of BSFL raised in an open system at the inclusion level of 12.50% without adverse effects on the growth, nutrient utilization, physio-metabolic status, and immune responses of Penaeus vannamei reared in brackish water.