Using waste substrates to produce insect meal for aquaculture feed

<p dir="ltr">The continuous growth of the aquaculture industry is constrained by the availability of sustainable feed options. New initiatives are required to fulfil the growing nutrition requirements of the aquaculture industry and the usage of insect meal is viewed as a promising solution. Black soldier fly (BSF) larvae are rich in overall nutrition and display bioactive properties. BSF farming requires low inputs and can be used for the bioconversion of waste materials whose disposal would otherwise incur environment and economic costs. The present study explored the suitability of utilisation of different waste streams; spent coffee grounds, cauliflower offcuts and brewery waste as substrates for BSF larval rearing. Results indicate that larvae raised on waste substrates have lower growth performance than those fed chicken feed. Spent coffee grounds were ineffective as an individual substrate while larvae fed cauliflower offcuts had higher yield and survival rates compared to those fed spent brewery grains but took longer to reach the prepupal stage. Macronutrient content (protein, lipid, and ash) varied with diet with spent brewery grains fed larvae showing the highest protein, lipid, and amino acid levels, surpassing those fed chicken feed, while the fatty acid composition of larvae did not notably vary among substrates.</p>