Efficiency and Improved Profitability of Insect-Based Aquafeeds for Farming Nile Tilapia Fish (Oreochromis niloticus L.)

SIMPLE SUMMARY: Fish farming in sub-Saharan Africa remains a source of livelihood for many househlods, but increased productivity is severely constrained by the high cost of fish feeds through the use fishmeal (FM) which is usually not easily available and when available is expensive. Therefore, this study evaluated the suitability of black soldier fly larvae meal (BM) as an alternative protein to FM. Four diet types were tested: control (100% FM; 0% BM), BM33 (67% FM; 33% BM), BM67 (33% FM; 67% BM) and BM100 (0% FM; 100% BM). The experiment was conducted for 20 weeks. The average daily feed intake and body weight gain of the fish were affected by the treatment diet. However, the survival rate and feed conversion ratio were not affected by the diet. The fish fed on diet BM33 had a 14.4% increase in weight gain compared to that of the control diet. Return on investment and the cost–benefit ratio were similar for various diets, suggesting that BM can be a suitable and cost-equivalent dietary protein substitute of FM in aquafeed for growing tilapia fish in earthen ponds for the market. ABSTRACT: In Sub-Saharan Africa, Nile tilapia (Oreochromis niloticus L.) make up over 80% of aquaculture production. However, the local aquaculture farmers are restricted by the unavailability and expensive cost of formulated rations. To reduce reliance on the scarce and expensive fishmeal used in fish feeds, alternative insect protein has been successfully utilized in many aquafeeds. However, data on the influence of insect-based feed on the growth and economic benefit of feeding tilapia with the emerging insect-based diet are scanty. This study investigated the effect of partially and completely substituting fishmeal with black soldier fly larval meal (BM) on growth and economic parameters of tilapia. The O. niloticus was fed a standard commercial diet as a control (100% FM; 0% BM), BM33 (67% FM; 33% BM), BM67 (33% FM; 67% BM) and BM100 (0% FM; 100% BM) for 20 weeks in randomly assigned cages mounted in an 800 m(2) earthen pond. Results from this study showed that diet type significantly (p < 0.05) affected the feed intake of the fish as well as weight gain. The feed conversion ratio and survival rate of O. niloticus did not vary across the different diets. Fish fed Diet(1) had a 15% increase in weight when compared to fish fed the control diet. Return on investment and the cost–benefit ratio was similar across the diets, suggesting that BM is a suitable and cost-equivalent dietary supplement of FM up to 100% in aquafeed for growing tilapia fish in earthen ponds for the market.