Alternative protein production for animal feed: Musca domestica productivity on poultry litter and nutritional quality of processed larval meals

The productivity of Musca domestica larvae reared on poultry litter and the nutritional parameters of insect meal as an animal feed ingredient have been evaluated. In laboratory bioassays, a seeding density of 0.32 g eggs/kg wet weight litter produced maximal yields of >50 g of naturally egressing larvae/kg substrate. Substrate composition and moisture content were critical determinants for insect development and generally litter wetted to water holding capacity (approx. 23% dry weight) was optimal for larval production. Four different processing methods were evaluated, but had no significant effects upon the nutritional quality of insect meals and all were effective in reducing microbial (Enterobacteriacae) populations to levels considered acceptable by feed regulations. Processed samples contained an average of 59.9% protein and 24.2% fat. Differences in levels of fatty acids, particularly palmitic, linoleic and α-linolenic were observed in larvae reared on different substrates. By contrast, highly similar amino acid profiles were derived from larvae reared on different substrates. With well-balanced amino acid profiles, superior to soymeal and more comparable to fishmeal, M. domestica larval meals have considerable potential for use as a protein-rich animal feed.