Abstract:
Aquaculture waste production has been a significant concern to health and the environment. Bioconversion of these wastes through insects are the promising environment-based solution. The present study focused on the bioconversion of aquaculture wastes by utilizing housefly larvae (HFL). On a dry basis, the proximate composition of HFL contains crude protein (38.91%), moisture (8.98%), fat (28.46%), fibre (9.04%), and ash (11.38%). Larval meal (HFL) was used as a fishmeal replacement in diets for Cyprinus carpio, formulated as a control, 25%, 50%, 75%, and 100% HFL integrated diet. The findings revealed significant morphometric improvements such as weight gain (WG) at 25%, length gain (LG) at 50% and 75%, and specific growth rate (SGR) at 75% and 100% HFL diet. The feed conversion ratio was significantly reduced in the 75% and 100% HFL diets. The protein efficiency ratio (PER) peaked with the 25% HFL diet. Feed properties like sinking velocity (SV) and water stability (WS) were optimized at 25% and 75% HFL diets. Histology, haematology, and serum biochemistry analyses showed notable enhancements with 50% and 75% HFL diets. Digestive enzyme activities (amylase, protease, trypsin) were higher in control and 25% diets, indicating efficient nutrient absorption. Antioxidant activity was most prominent in the 100% HFL diet except for the lipid peroxidation shows better activity in control. Overall, the present study recommended that HFL meal can replace fishmeal in aquafeeds, with up to 75% inclusion improving C. carpio growth and health.
Keywords: Aquaculture, Bioconversion, Cyprinus carpio, Housefly larvae, Larval biomass, Fish meal.