Researchers worldwide are interested in utilizing insects as a sustainable source of animal feed.

Insect meal is a nutritious ingredient made from processed insects, meaning that the insects are dried, ground, and sometimes defatted. Common species used for insect meal include black soldier fly larvae, crickets, mealworms and houseflies. While it might seem unusual at first to consider insect meal as a feed source for animals, species like poultry and pigs naturally consume insects every day.

Many factors contribute to the increased interest in using insect meal as a feed component for livestock, including its nutritional value. Insect meal provides proteins and fats suitable for production animals’ requirements, Kristy DiGiacomo, associate professor at The University of Melbourne, Australia, said via email. Research has shown that insect meal is a rich source of protein, amino acids, and minerals like calcium, phosphorus, and zinc, with a high digestibility rate.

Perhaps more interesting, though, is how insects can be rapidly produced and contribute to a circular economy. DiGiacomo explained that insects can bioconvert many organic and potentially inorganic substrates, including vegetables, fruits, grains, manure, and animal remains, into a nutritious product (insect meal). In other words, insects can be reared with a variety of substrates as a food source, meaning that waste, such as that coming from a supermarket, could be used as feed. Additionally, insects produce frass, a term used to describe insect poop and exoskeleton waste, which can be used as a fertilizer product.

“Globally, feed production systems are changing in line with climate change and changes to consumer demands,” DiGiacomo said. “Livestock producers are responding to these changes by diversifying and innovating, and insects are one part of such developments.”

DiGiacomo also added that the desire to pursue insects as feed is driven by a desire to reduce environmental footprints, increase sustainability, and reduce reliance on traditional feed proteins and imported feed ingredients. Additionally, insects provide an alternative revenue stream, especially when rearing facilities can be embedded into existing production systems.

There are different systems under development for rearing insects on a commercial scale, DiGiacomo added. Generally, the process involves processing feed, which is then inoculated with insect larvae obtained from a breeding stock. The insects are left to feed, and once they reach an appropriate size, they are separated from the frass and processed.

There are large-scale and small-scale production facilities for insects. On the large end are companies like EnviroFlight in the U.S. EnviroFlight commercially produces black soldier fly larvae in Kentucky, growing the insects in vertically stacked trays. The insects are reared for 18 to 20 days before they’re harvested and processed into ingredients. The commercial facility manages more than five billion flies each year and more than 30 billion larvae, as reported by the North Carolina Biotechnology Center.

However, it’s also feasible to raise insects for feed at home. Purdue University offers a guide online for raising black soldier fly larvae, including instructions on how to build a rearing bin. Larvae raised at home can be used both as a feed source for animals and to improve composting.

While insects as feed present a lot of benefits for the industry, there are still barriers to the practice becoming widely adopted.

“Current challenges are mainly around engineering and scaling up of production. To meet the demand of large industries like poultry and pork, the production of insects needs to be in large and consistent volumes,” DiGiacomo said. “This also requires adequate feed stocks to rear the insects with, and consistent sources can be difficult to maintain. Finally, regulation and legal barriers still exist that can prevent the use of insects as livestock feed.”

In the U.S., black soldier fly larvae protein has been formally approved for use in adult dog food by the Association of American Feed Control Officials, a non-profit organization composed of federal and state officials who oversee animal feed laws and collaborate with the U.S. Food and Drug Administration Center for Veterinary Medicine. This is the only insect species approved so far in the U.S. feed supply chain. The EU has authorized insect proteins in fish, poultry, and pig feeds. Unlike the EU, the U.S. has not undertaken a centralized policy or guidance framework for insects as feed, making progress a bit slower and up to individual companies.

Interestingly, companies are allowed to sell dried mealworms and other insects for livestock like poultry because they are labeled as “treats” and not feed. This is a gray zone of regulatory oversight, especially in the backyard and hobby farming market. Ingredients for commercial farms face higher regulatory scrutiny.

“While it’s unlikely that insects will ever fully replace other feed protein sources for production animals, they can potentially provide a valuable additional option for producers,” DiGiacomo said.