How Crickets Can “Upcycle” Bad Grain Into Useful Animal Feed – Entomology Today

By Grant Bolton, Ph.D.

There’s fungus among us, and it’s everywhere. That’s especially true for corn.

The fungus Fusarium verticillioides is most commonly associated with corn, and it produces a toxin called fumonisin. This mycotoxin (“myco” being a prefix meaning fungus) isn’t too much of a problem because it’s closely monitored in the animal-feed industry, but it can cause health issues for both livestock and human consumers if the toxin levels are too high.

But what does this have to do with insects?

Researchers at the U.S. Department of Agriculture’s Agricultural Research Service (USDA-ARS) are exploring how contaminated grain could still be put to use by feeding the grain to crickets.

“There is encouraging research to replace insect meal for soybean meal and fishmeal,” Paulk says. Demand is growing for alternative protein sources in animal feed, as soybeans require significant amounts of water and land, while fishmeal production is resource-intensive and disruptive to food security. Crickets and other insect-based feed sources are easy to rear and have a much smaller environmental footprint.

For their study, the researchers fed house crickets (Acheta domesticus) a standard cricket diet that included a large proportion of corn and three levels of purified fumonisin, plus a control group. After feeding on the treatments for 34 days, there was no significant difference in mortality or growth between the groups. In short, the crickets weren’t affected by the mycotoxin at all.

“It was encouraging to see mortality rates were not affected by the mycotoxin,” Paulk says. “The mycotoxins go straight through the cricket, and that seems to be the case for a lot of insects. There’s immediate excretion of fumonisin, and there doesn’t seem to be any metabolizing or breaking down of fumonisin, either. The fumonisin was found primarily in their frass.”

If crickets, mealworms, or black soldier flies can be fed agricultural byproducts that are contaminated and harmful to vertebrates and still be used to produce a safe, high-protein meal, then that offers great benefits to sustainability in the livestock feed industry. It could help reduce the costs of preventing and managing mycotoxins in low-quality feed, “upcycling” it to a more nutritional product.

However, insect rearing has its own set of challenges and limitations, and further research is needed. Additionally, insect meal can be more expensive than traditional sources like soy or fishmeal. More insects, different insects, and other mycotoxins should be studied, Paulk and colleagues say, but this preliminary research offers a tremendous opportunity for alternative ways to feed livestock.

“If we can reduce waste from agricultural systems and create another ingredient in animal feed at the same time, that’s a win in my book,” Paulk says.

The research conducted by the USDA-ARS represents a significant stride toward reimagining our agricultural waste management practices and enhancing the sustainability of animal feed production. By showing that crickets can safely consume and thrive on grain contaminated with fumonisin, this study opens the door to a new approach to using low-grade byproducts for traditional livestock. The ability of insects like crickets to convert agricultural waste into high-quality protein reduces the environmental impact of waste disposal and introduces a more sustainable and eco-friendly protein source into the animal feed industry.

By reducing waste, enhancing feed efficiency, and contributing to a circular economy, insect-based feed could indeed play a pivotal role in shaping the future of agriculture.