JEFFERSON, Ga. — The ongoing struggle with highly pathogenic avian influenza continues from this outbreak that began in 2022. How to manage mortality disposal, minimize spread and eliminate the virus are incredibly challenging concerns.
Dr. Casey Ritz, a professor, Extension poultry program coordinator, and associate head of the University of Georgia’s Department of Poultry Science, recently addressed mass bird mortality disposal following an HPAI outbreak, during a session of the 2025 Georgia Broiler Conference.
Several factors are considered when choosing a disposal method following an HPAI event on a poultry producing premises. The first factor is biosecurity.
“We have to maintain biosecurity as much as we can,” Ritz said. “Using on-site methods such as in-house composting are preferred because they reduce the risk of spreading the virus during transport.”
Other factors, he noted, include: The scale of the outbreak, because widespread outbreaks may require the usage of a variety of disposal methods due to the volume of birds. Logistical resources need to be considered regarding the availability of equipment and trained personnel. The environmental impacts of composting and potential landfilling; and regulatory approval because every state is different and methods must be approved by state and federal animal health officials.
Other considerations include the rapid degradation of carcasses and achieving virus inactivation, because the bird flu virus can survive for a long time, Ritz added.
“This needs to be in the front of our minds in understanding the impact that the virus can have under the right conditions,” he said.
Regarding mortality volume, Ritz provided, for example, a 4-house turkey farm in the Midwest with 32-pound average toms can be up to 1.3 million pounds; a 1.5 million layer operation, with 5.5 pound average birds can equal 8.3 million pounds of dead chickens; and an 8-house Georgia broiler farm, with 6-pound average birds can be 1.6 million pounds.
“Also, don’t forget, all the litter, eggs, and feed must all be disposed of, as well,” Ritz noted. “It all has to be dealt with in one way or another, whether it be compost; it all has to be in the mix. If it is buried, it all has to go into the mix.”
Several disposal methods are potential options, however, many pose challenges that make them not the most viable.
On-site burial is no longer an option in many locations because of the potential leaching of bacteria in burial pits into groundwater.
“While historically used, on-site burial is not a preferred method in many states due to concerns about groundwater contamination and the potential for the virus to persist in the soil,” Ritz said.
Biosecurity issues also make landfilling not a number one option either, he noted, adding that some landfills may accept dead animal mortalities, and others may not. It has to be a lined landfill, and proper cleaning and disinfection procedures need to be followed to lower any biosecurity risks.
For incineration, temperatures can reach 1,400 to 1,600 degrees F but, he added that, some of the considerations include scheduling of equipment, location and environmental impact, fuel costs, ash disposal, state permitting, as well as the time it takes to conduct, with carcass throughput at 1,000 pounds per hour.
“At a thousand pounds an hour, how long would it take to incinerate an HPAI infected broiler farm?” Ritz asked, answering, “67 days. It’s not a timely method. For disposal, what we have found, essentially, is that it is a combination of things.”
Composting
“This has been the number one way that we have dealt with the mass quantity of mortalities, essentially for the past 10 years,” Ritz said. “About 85 percent of all of the cases of HPAI … we have used composting as the primary method of disposal. It is a natural process and has everything we need to inactivate the virus as quickly as we can.”
The USDA’s HPAI response protocol for successful mortality composting an infected flock, he noted, cites that a qualified expert is needed to guide windrow construction, there need to be trained equipment operators, there must be sufficient carbon, space and water. If any of these components are not met, composting will not be the recommended method of disposal.
Composting inside a poultry house, Ritz added, minimizes biosecurity risks and access to the compost by scavenger animals.
“The USDA avian influenza mortality composting protocol requires a 28-day composting process,” he added. “The goal and outcome is for viral inactivation — not high-quality compost.”
In choosing a compost site, locations where the wind direction does not travel to nearby residencies is preferred, whenever possible, Ritz noted, adding that locations should have a 2 percent to 4 percent slope to encourage on-site drainage, soil depths exceeding 36 inches to bedrock, and not located on a flood plain, along with several other considerations that follow federal protocol such as diversion ditches and setbacks.
“There are only a few viable methods available to us for mass poultry mortality disposal,” Ritz said. “Composting is the preferred disposal method, though method selection can be site dependent.”
He also noted that the actual techniques to maintain safety from bird flu are biosecurity protocols for prevention.
“Even though we have folks that are prepared for it, through response teams and federal and state agencies,” Ritz added, “It is a real challenge.”
