By Isaac Sacco, Students Promoting Awareness of Research Knowledge (SPARK)

Natural process converts chicken manure into value-added products

Flies and manure have long had a strong symbiotic relationship, but now University of Guelph researchers are capitalizing on this partnership to create a solution to manure problems that are literally piling up for chicken farmers.

Prof. Youbin Zheng, School of Environmental Sciences, and graduate student Nichelle Lomas have been investigating the use of fly larvae to convert chicken manure into value-added fertilizer and high-protein animal feed, and to reduce manure’s smell and transportation costs.

Once processed, the manure becomes an organic fertilizer and the larvae (or puparia) can be used as animal feed.

“Basically we are just taking what Mother Nature already does and trying to do it on a much larger and more efficient scale,” says Zheng, who is also U of G’s Chair in Environmental Horticulture. “Purely organic fertilizer is hard to come by in the market. Our process is unique in the fact that it is organic, high quality and bountiful.”

Zheng and Lomas have shown that by adding fly eggs to piles of fresh manure, the mass of the manure could be reduced by about 75 per cent and moisture content by 90 per cent. When the fly larvae hatch they process organic matter and add oxygen to the mass, significantly reducing its weight and odour.

The researchers say the once foul-smelling manure turns into a light, odourless and nutrient-rich fertilizer within a week.

The chicken industry is currently making the transition to using fewer barns with larger chicken populations. With more chickens comes more manure: an average-size barn can produce about 10 tonnes of manure each day.

Manure is usually composted by piling it outdoors, where it takes many months for it to become fertilizer and for the odours to subside. The weight and volume of composted manure can also make distribution an issue.

“What we are proposing is a win-win solution for everyone involved,” says Lomas. “The manure is converted into a profitable fertilizer, which is organic and full of nitrogen and other nutrients.”

The team, which includes industry partner Ecospace Engineering, has built a prototype manure converter. The team’s next steps include trying to develop a commercial-scale machine that is self-contained and can process large amounts of manure.

The researchers are also developing a method of dealing with the flies that are byproducts of this process.

Zheng says he is confident that this technology would be sought after by farmers because it solves a manure problem while also generating potential revenue through a fertilizer or animal-feed retail opportunity.


Other researchers involved in this project include Profs. Steve Marshall and Mike Dixon, School of Environmental Sciences. This research is funded by the OMAFRA – U of G Partnership. Additional funding is provided by Ecospace Engineering and Root Rescue.