Potential of Black Soldier Fly Larva (Hermetia Illucens L.1758) as an Alternative Protein Supplement in Nile Tilapia (Oreochromis Niloticus L.,) Feed

With fish depletion in Lake Victoria, there is an emerging competition for silver cyprinid fish Rastrineobola argentea (‗Omena‘) between human consumption and fish aquaculture feed formulation. Subsequently, fishmeal has increasingly become expensive with feed cost accounting for around 70% of variable costs in fish farming. Therefore, this study focused on using black soldier fly larva as a substitute for fishmeal with the following objectives 1. To evaluate the growth performance of O. niloticus fed on a diet supplemented with H.illucens larva meal as a source of protein and; 2. To identify the most cost effective diet supplemented with H.illucens larvae as a source of protein for O.niloticus. The study focused on using H. illucens larva as a supplement in O.niloticus diets as an alternative to fishmeal. For objective one, five test diets were formulated with strategic inclusions of H. illucens at (0, 25, 50, 75 and 100 %). Growth parameters namely length, weight and survival data were sampled fortnightly. Objective 2 was investigated by using the enterprise budgets on the relative profitability of the fish fed on varying H. illucens levels and fishmeal. Statistical comparisons were performed by One Way Analysis of Variance (ANOVA), One-way Analysis of Covariance (ANCOVA) and multiple linear regression analysis using Statgraphics ver16 and R-Statistical Software version 3.5.3. After controlling for time (days), there was a significant difference in the treatment effect on length (p< 0.05). Days equally had a significant effect on growth performance (p< 0.05). Moreover, the interaction effect between treatment and time was significant (p<0.05). In terms of weight, after controlling for time (days), there was a significant difference in the treatment effect on weight (p<0.05). Days equally had a significant effect on growth performance (length and weight gain) (p<0.05). Moreover, the interaction effect between treatment and time was significant (p< 0.05) with R2 of 0.98 for length while weight (p<0.05) with an R2 of 0.96. This study found that O.niloticus fed diets containing 25% H. illucens outperformed the control (FM) treatment in growth performance. There were no significant differences between the FM (control) and feed supplemented with H. illucens at 50%. However, growth performance declined at 75 and 100%, which led to the conclusion that increased levels of H. illucens in the diet due to inadequate supply of amino acids and increased chitin levels caused a decline in growth. In terms of economic analysis, O. niloticus fed increasing levels of H. illucens was more profitable at 50%, 75% and 100%. These findings indicated that O.niloticus feed can effectively be supplemented with H. illucens as a protein without adverse effects on growth performance. The study clearly indicates that aquaculture farmers and feed manufacturers can use H. illucens instead of fishmeal in feeds thereby lowering production costs and increasing food security. Furthermore, farmers should increase their economies of scale and only sell fish once they reach market size in order to increase aquaculture profitability and meet the food and nutritional security agenda.