Craig Sheppard, an entomologist with the UGA College of Agricultural and Environmental Sciences, says a certain not-so-picky maggot would be more than happy to help clean up Georgia chicken houses.
Sheppard has developed a system using the black soldier fly. The system could reduce the bulk of the manure by half and supply added income by selling the maggots as feed for animals.
"We can get rid of the manure and in the process help the farmer make more money," Sheppard said. "It will also help the farmers with their nutrient management problems."
|Soldier fly maggots could dispose of half of Georgia's growing poultry manure problem and make farmers some money doing it.|
As Georgia's poultry industry continues to grow, management practices will have to be developed to handle the manure, said Glen Harris, a UGA Extension Service scientist.
"Anybody that produces animal waste is going to have to have some sort of manure management plan that uses the manure in an environmentally friendly fashion," Harris said.
A practice gaining in popularity uses chicken manure to fertilize crops. Experts recommend 2 tons of manure per acre. Theoretically, Georgia has enough cropland to use up the chicken manure produced each year. But Harris said hauling it to distant fields costs too much.
New environmental regulations could also cut back the amount of manure farmers are allowed to spread in fields, he said.
"The biggest problem is the excess nutrients in manure," he said. "We can't distribute it all. There is only so much cropland and safe places to distribute the waste close to the layer houses."
"We will eventually get to where there won't be a single way to handle the manure," Harris said. "But we will develop a number of different ways to get the manure distributed."
Sheppard's system works in chicken houses with egg-laying hens. Georgia hens produce more than 240,000 tons of chicken manure a year.
The manure is allowed to fall to the maggots under the floor of the chicken house. By itself, a maggot is only about an inch long and one-fourth inch in diameter, Sheppard said. But if you get enough of them, they can eat tons of animal waste.
Insects go through three major stages: larvae, pupae and adult. As the black soldier fly transforms from a larva to a pupa (the prepupa stage) it crawls out of the manure and sheds its skin and the lining of its gut. It then buries itself, he said, and gets ready to become a fly.
With Sheppard's system, the prepupa uses a ramp to crawl out of the manure. At the end of the ramp, it falls into a holding pit. The collected prepupae can be fed straight to animals or milled into other feed sources.
"I'm working on a system that can produce the larvae year-round," he said.
A full maggot is 42 percent protein and 35 percent fat. A large collection system can yield 58 tons of prepupae in five months, he said.
"We want to help the farmer make more money," he said. "We can turn the manure into $500 per ton feedstuff. That could mean as much as $30,000 a year."
The maggots could also help manage swine waste and possibly human waste, he said.
Many types of maggots like to feed on animal waste. But Sheppard prefers the black soldier fly because it's harmless to humans. It also, through competition, reduces housefly populations.
"When the soldier fly matures, it usually goes to the woods," Sheppard said. "So, it's not a pest to humans."