Optimal substrates for producing housefly larvae with high nutritional composition for sustainable poultry feed in Niger

Poultry farming, because of its many potentialities (i.e. short duration of reproduction and production cycle, rapid return on investment), occupies a place of choice in development strategies and the fight against poverty in most African countries. In Niger, West Africa, poultry are fed specific protein-providing feed ingredients (such as fishmeal); however, these ingredients are very expensive and unsustainable. Larvae represent a potential alternative source of protein for poultry. Here, we investigated different substrates to optimise housefly ( Musca domestica L. 1758) maggot production and nutritional composition. Eight dry substrates were tested. The highest larval biomass (larval biomass produced by 10 mg of house fly egg placed on 50 g dry substrate) and mean weight (individual house fly larvae 5 days after the incorporation of eggs on the substrate) were observed on millet and wheat bran (3,446.67±134.16 mg and 24.00±1.01 mg, respectively). However, larvae produced on Brewer’s spent grains had the highest protein and lipid content (53.79±1.04% and 24.13±5.20%, respectively). Ash content was highest for larvae produced on cow dung and a mixture of 50% wheat bran and 50% cow dung (15.01±0.32% and 15.41±0.09%, respectively). Maggots produced on rumen contents had the highest water content (80.89±0.22%). The profile of produced larvae included palmitic acid (30.99±0.48% on grain), palmitoleic acid (30.26±2.84% on cow dung), oleic acid (27.93±0.31% on rice hulls), and linoleic acid (26.41±0.18% on millet bran + rumen contents). For all substrates, Maggots contained more unsaturated fatty acids (57.59-66.52%) than saturated fatty acids (26.54-46.34%). This study, offers to farmers a wide variety of substrates that could be used to produce maggots, providing a sustainable source of protein that has not been previously available in Niger. We recommend the farmers to use the cow dung to produce maggots without cost.