The common house fly (Musca domestica) could be deployed to reduce manure mass on farms and then harvested to create a protein-rich larva-meal ingredient for livestock feed, according to a new study. (Photo credit: Joseph Berger, Bugwood.org)

As the global human population continues to rise, researchers are turning to the potential role insects might play in growing the global food supply. A new study from researchers at Cornell University points to the house fly (Musca domestica) as a viable source of a protein-rich food source—not for humans, but for livestock.

As reported in PLOS One, the house fly’s capacity for nutrient recycling means it could be raised on cow manure and then extracted to create a larva-meal ingredient for feeding livestock or farmed fish, thus playing a dual role in both biodegrading manure and supplementing livestock food sources. The research team at Cornell’s College of Agriculture and Life Sciences experimented with varying densities of M. domestica larvae in cow manure and measured their growth rate, the manure degradation, and the nutrient content of the extracted larva meal.

They found the manure to be an effective source for supporting M. domestica larval growth, and the rate of manure degradation was as much as 26 percent greater in samples with larvae present than in those without. The larva meal generated from the manure-raised larvae was found to have similar combinations of protein, minerals, amino acids, and fat to that of other high-protein feed ingredients, such as fishmeal.

Currently, regulations vary around the world on the use of insect-derived food for livestock. The U.S. Food and Drug Administration would require that insect-derived additives for animal feed meet its “Generally Recognized as Safe” criteria. None the less, interest in the practice is growing, and researchers have been building a body of knowledge on insect-derived animal feed.

The Cornell researchers suggest their study adds further evidence of its potential value. “Overall, our results support that farming insect larvae has significant potential to develop as a novel mainstream agriculture operation and address several critical needs, but there is also urgent need for recognition of this approach. Federal research funding, private enterprise investments, and establishment of policy and regulations surrounding production and use of larva meal are necessary to compose a framework for commercial production and make this industry successful,” they write.

Read the full study: “Sustainable production of house fly (Musca domestica) larvae as a protein-rich feed ingredient by utilizing cattle manure,” PLOS One. And, also see the Annals of the Entomological Society of America‘s recent Special Collection: Filfth Fly-Microbe Interactions.