APPLICABILITY OF WASTE-REARED Hermetia illucens AS AN INGREDIENT IN THE DIET OF NILE TILAPIA Oreochromis niloticus

We conducted an eight-week feeding trial to assess the applicability of Black Soldier Fly Larvae (Hermetia illucens) meal (BSFLM) and oil (BSFLO) as feedstuffs in the diet of Nile Tilapia. The BSFL used in this study was reared on dried distiller's grains with solubles (DDGS), and then was processed to produce meal and oil. Three diets were formulated to contain 32% crude protein (CP) and 8% lipid. The control diet (Control) was formulated to derive most of its CP and lipid from fishmeal (FM), soybean meal (SBM), fish oil (FO) and soybean oil (SBO), respectively. The first test diet (BSFLM) was designed to replaced all FM and most of the SBM in the Control with BSFLM. The second test diet (BSFLM&O) was formulated identically to BSFLM except for a complete replacement of FO with BSFLO.

Each diet was fed twice daily and to apparent satiation to triplicate groups of 10 juvenile tilapia (49 ± 1.5g) stocked in 100-L rectangular fiberglass tanks operating as a recirculating aquaculture system. The results (Table 1) revealed statistically significant reductions in feed efficiency ratio (FER) and protein efficiency ratio (PER) for fish fed the BSFL-based diets, while final weight (FW), weight gain (WG), specific growth rate (SGR), survival (S) and  condition factor (K) were unaffected (P>0.05). In addition, no significant dietary effects on health-related blood parameters (not shown) of the Nile tilapia were observed.

Our results indicated that BSFL-derived meal and oil evaluated in this study have lower nutritional value relative to FM, SBM, FO and SBO. However, the BSFL-based diets were readily accepted by the fish and supported similar growth rates. Therefore, this study demonstrated that waste reared BSFL-derived feedstuffs are suitable feed ingredients for Nile tilapia. Further studies to optimize BSFL-based diets for cultured fish species are warranted.