Disposing manure could yield new livestock feed

Published on: Aug 13, 2013

Two negatives — cow manure and flies — can make a positive: Cornell animal scientists, entomologists and a business professor will examine the environmental impact and commercial potential of quickly processing dairy cow manure with fly larvae, and then using the dried larvae as livestock feed.

For dairy farms, manure waste presents an ongoing disposal challenge, while at the same time, the common housefly is considered a public health problem. With a 2013 grant from Cornell's David R. Atkinson Center for a Sustainable Future, the researchers hope to exploit the housefly's life cycle and hasten manure's decay process — to make it into a usable fertilizer in as little as eight days. The residual larvae may then be dried and made into high-quality protein supplements for aquaculture and livestock.

"Manure is a natural substrate for fly larvae. We can decrease manure volume, control for nutritional content and decrease its potential for eutrophication (leached, heavy doses of nutrients in water bodies)," Vimal Selvaraj, Cornell assistant professor of animal science and the principal investigator on the grant, said.

While collected larvae will be dried and ground into meal to replace soybeans or fish meal in animal feed, additional toxicological safety testing for heavy metals, residual drugs and antibiotics will be examined, the researchers added. n