Impact of Different Organic Substrates on the Productivity and Nutritional Composition of Black Soldier Fly Larvae (Hermetia illucens)

Abstract

Black soldier fly larvae can clean up the environment by transforming low-value organic waste into high-nutrient proteins, which can be used in livestock farming, including aquaculture. The objective of the study was to assess the effect of the composition of various organic substrates on the productivity and nutritional quality of black soldier fly (BSF) larvae. Four treatments (T1, T2, T3, T4) are based on organic materials (brewer's grains, palm kernel cake, soybean okara, (Moringa oleifera) leaves, marine fish and poultry viscera) in defined proportions. The chemical analyses carried out on the substrates are: pH, moisture, total nitrogen, assimilable phosphorus, potassium, dry matter, ash and those on the BSF larvae concern: protein, fat, dry matter and ash. The experimental set-up used is a completely randomized block of 12 tanks arranged in triplicate. The loading density was 5750 larvae per kg of substrate. The experiment lasted 14 days. No significant difference was obtained between the pH values (p>0.05) of treatments T1, T3 and T4. The highest results for moisture, total nitrogen, and assimilable phosphorus were obtained in treatments T3 (marine fish viscera) and T4 (poultry viscera) (p˂0.05). Also, the best (final weight, weight gain per larva and survival rate) and nutritional qualities (proteins and lipids) were recorded in BSF produced from treatments T3 and T4 (p˂0.05). We can therefore conclude that the quality of the production substrate influences the productivity and quality of the BSF produced. Such a substrate, rich in chemical and nutritive elements, improves the productivity and quality of the BSF.