How to compost 150,000 chickens
“For composting to be done right, you need a carbon-rich, dry feedstock”
January 11, 2016 by Mauricio Espinoza
One of the main challenges posed by the avian flu outbreak that has impacted the U.S. poultry industry in the past year is how to safely and effectively dispose of potentially hundreds of thousands of birds killed as a result of infection and eradication efforts.
“The U.S. strategy is to quickly identify the infected premises, depopulate, properly dispose of carcasses and manure, clean and disinfect the premises, and have 21 days of down time after cleaning before re-population can take place,” said Mohamed El-Gazzar, Ohio State University Extension’s poultry veterinarian. “As you might imagine, the logistics of depopulation and disposal are very challenging, particularly with the large-scale layer complexes, some of which have a capacity of more than 5 million birds.”
While the avian flu outbreak did not impacted Ohio poultry, experts with the College of Food, Agricultural, and Environmental Sciences at The Ohio State University have been helping poultry producers learn about the disease, boost biosecurity measures on the farm, and prepare to minimize the flu’s impact if it were to reach the state.
To address the challenge of safe disposal in the event of an outbreak, El-Gazzar sought the collaboration of Fred Michel, a biosystems engineer with the Ohio Agricultural Research and Development Center OSU Extension composting specialist. OARDC and OSU Extension are the research and outreach arms, respectively, of the college.
Michel said there are four ways to dispose of such large numbers of dead animals at a time: incineration, onsite burial, landfilling and composting.
“Incineration is difficult and expensive and there is not sufficient capacity,” he said. “Onsite burial is a possibility, but the areas where many Ohio poultry farms are located have high water tables and there may be issues with ground water contamination.
“Landfilling can be effective, but it increases the risk of spreading the disease to other areas during transportation. So, onsite composting seems to be the best option, as it would prevent contamination of water, effectively destroy the pathogen and eliminate the risk of spreading the disease to other farms.”
However, Michel said, there were some issues that needed to be addressed when he started considering a plan for on-farm composting of large numbers of birds.
“Fact sheets on composting birds currently available around the country only address the process of composting a few birds at a time, not the large number involved in a catastrophic event,” he said. “So we had to come up with the right formula and method to make this type of composting work.”
Additionally, composting hundreds of thousands of birds at commercial farms would require a large amount of carbon-rich amendment material, such as sawdust, wood chips, yard trimmings or straw.
“For composting to be done right, you need a carbon-rich, dry feedstock,” Michel said. “Birds are low in carbon and too wet. So an amendment material is needed to compost them.”
For egg-laying operations, Michel designed a slab composting method that includes a one to two foot base of wood chips or mulch, followed by layers of chickens, finished compost and mulch. The top and sides of the slab are covered with amendment material, which insulates the slab and helps prevent leakage and odors.
A pile measuring seven feet high, 100 feet long and 100 feet wide – approximately one-fourth of an acre – would be needed to compost 150,000 birds at the same time, Michel said. Such a pile would require approximately 2,600 cubic yards of amendment material.
“The pile is left without mixing for at least two weeks,” Michel said. “The temperature generated by the composting process will kill the virus. After this, the pile could be left to further degrade or be turned.”
For broilers and turkeys, the method of composting would vary because of different production practices.
“You could just use the bedding material that’s already in the broiler or turkey houses and mix the dead birds in. Then you make a windrow (a long, low heap of composted material) inside the facility,” Michel said.
In addition to developing a spreadsheet for the design of large-scale poultry composting based on the slab method, Michel created an online map that includes the location and contact information for businesses that sell amendment materials. All of this information is available on the Ohio Composting and Manure Management (OCAMM) program’s website, www.oardc.ohio-state.edu/ocamm/.
Mauricio Espinoza is a writer with the Ohio State University College of Food, Agriculture & Environmental Science