The majority of Tennessee birds killed due to avian flu (either by contracting the virus or by euthanasia after exposure to limit an outbreak) have been in commercial facilities, according to the USDA. (Photo: John Partipilo)
Ongoing bird flu outbreaks continue to ravage commercial poultry flocks in Indiana and Ohio, where two counties issued emergency declarations this week. But Tennessee appears to be faring better, at least for now.
“It’s not that we have not been affected, but we have not been affected by avian influenza near as much as what some other states have,” said Tom Tabler, statewide poultry extension specialist at the University of Tennessee.
The current outbreak of the highly pathogenic avian influenza (HPAI) virus has been detected in wild, commercial and backyard flocks since February 2022, according to the CDC. The virus is deadly to chickens and turkeys and is typically spread by wild migratory birds.
Under current U.S. Department of Agriculture policy, if one bird tests positive in a commercial flock or backyard coop, the entire flock must be euthanized in an effort to stop the spread, Tabler said. Nearly 163 million birds have been affected across the U.S. since early 2022, including 9 million birds in Ohio within the last month.
Tennessee has seen 456,070 birds affected since the outbreak began in 2022, according to the U.S. Department of Agriculture’s data dashboard. The majority of those birds were from five commercial flocks.
Tennessee’s last reported detection was in a non-commercial flock of 30 birds in Greene County on Jan. 16, according to USDA data.
Nobody seems to know why just yet, but broilers do not seem to be quite as susceptible to avian influenza as table egg laying flocks and turkey flocks.
– Tom Tabler, University of Tennessee Extension
A commercial operation in Gibson County reported 37,700 birds affected in late November, the most recent commercial-scale outbreak in Tennessee. The state’s most impactful string of five outbreaks struck Weakley County in December 2022, resulting in the deaths of 397,100 birds from commercial breeders.
While Ohio and Indiana are among the country’s top egg producers, Tennessee’s main commercial product is broiler chickens — birds raised for meat.
“Nobody seems to know why just yet, but broilers do not seem to be quite as susceptible to avian influenza as table egg laying flocks and turkey flocks,” Tabler said. He posited that broiler chickens are usually processed when they are young, while laying hens can be older.
The USDA recently granted a conditional license for a bird flu vaccine for use in chickens, but the vaccine has not yet been cleared for commercial use or sale. That strategy is also complicated by trade relationships — some trade partners will not accept exports from countries that allow vaccinations, said Jada Thompson, a professor of agricultural economics at the University of Arkansas.
There is no treatment for the virus, leaving biosecurity practices as the best line of defense for commercial and backyard flocks alike, Tabler said.
But those practices might be a new concept to novice chicken owners.
What is biosecurity?
Commercial producers are used to biosecurity practices, Tabler said, “because this is not the first go-around the U.S. has had with avian influenza.”
A smaller outbreak in 2014 killed about 50 million birds — at that time, the largest HPAI outbreak in U.S. history.
Tabler describes biosecurity as a three-legged stool: isolation, traffic control and sanitation. To have sound biosecurity, all three are key.
Isolating flocks from any exposure to other birds that might be carrying the virus can reduce risk, he said. The same logic goes for traffic in and around areas where flocks are raised and kept — whether that is vehicle or foot traffic.
Wild birds spread the virus through nasal secretions and fecal material, which can end up being tracked from one location to another on boots, tires or through other means.
That’s where sanitation comes in. Commercial producers may use foot baths at the door of chicken houses, or may require the use of disposable boots or shoe covers, Tabler said.
“Right now, nothing can be too clean,” he said.
Tennessee is home to several large-scale chicken processors, including Tyson Foods, Koch Foods, Perdue Foods and Pilgrim’s Pride.
Tyson Foods opened a poultry complex in Humboldt, a city in Gibson and Madison counties, in 2021. The company did not respond to requests for comment, but its website states that all of its U.S. poultry operations “continue to operate under heightened biosecurity.”
That includes limiting non-essential visitors, disinfecting vehicles before they enter farms and special uniform and footwear requirements. All flocks are tested before they leave the farm, the website states.
Backyard biosecurity doable but ‘takes more time’
The number of backyard flocks in Tennessee is nearly impossible to measure. Anyone can have backyard chickens so long as they comply with local ordinances, Tabler said, and they aren’t required to register like commercial flocks do.
“It is unbelievable how popular backyard chickens have become just in the last five or six years since the pandemic,” he said.
But people who are new to caring for backyard chickens may need more education on biosecurity measures, something Tabler and county agents throughout the state are trying to promote through talks and online resources.
Backyard flock owners can implement biosecurity measures without too much difficulty, “but it does take more time” and attention, he said.
Any place that flock owners congregate presents a risk of transmission, Tabler explained. Manure can be tracked in and out of popular feed stores or coffee shops, he said, and if an owner doesn’t take precautions to change shoes or clothes before making contact with their chickens, “that increases the risk factor.”
The H5N1 virus is also being seen in mammals like bears, raccoons, skunks and possums, because they may feed on dead birds that carry the virus, Tabler said. The flu has also been seen in dairy cows and in humans (U.S. dairy and poultry workers), according to the CDC. Tennessee hasn’t logged any cases in humans.
But the CDC hasn’t documented person-to-person spread as of Feb. 20, and it classifies the public health risk to humans as “low.”
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