Insect meals (IM) are considered as a sustainable alternative protein source in fish diets in response to over-exploitation of fish meals (FM) and their increasing costs.
In this study, crescent substitution up to total replacement of FM with IM from black soldier fly (BSF) larvae (Hermetia illucens, L.) was tested for feeding Nile tilapia (Oreochromis niloticus) juveniles, during two months. Four isonitrogenous and isoenergetic diets were formulated for testing a standard control diet containing 180 g FM/kg versus three experimental diets in which 33.3, 66.6 and 100% of FM was replaced with BSF meal.
The results showed that the fish fed with the diets containing the BSF meal had better growth performances (final body weight and specific growth rate) than the fish fed the FM diet. In the same way, daily feed intakes (FI) were higher for fish fed the BSF2 and the BSF3 than for those fed with the control diet. The value obtained with BSF1 was intermediary, not differing with the others.
Neither the feed efficiency (Apparent Digestibility Coefficient (ADC) of crude protein, Feed Conversion ratio (FCR) and energy in diets) and nor muscle protein and lipid composition were affected by replacing the FM with the BSF meal.
Moreover, the composition of fatty acids in fish muscles were similar although the experimental diets contained less n-3 fatty acids than the control diet.
Our results clearly indicate that BSF meal is a good source of protein and lipids for Nile tilapia juveniles and that it can totally replace FM in their diets with improved growth performances.
Considering the evolution of production and decreasing price of insect meal as well as the unavailability of fish meal, BSF meal may be an economical and sustainable feedstuff for Nile tilapia.