California is experiencing a fall wave of highly pathogenic avian influenza — or H5N1 — among both dairy and poultry operations. The major outbreak in Central Valley dairies has led to creation of a joint industry and government effort to identify, track and treat affected commercial operations.
As of Tuesday, the count of infected dairy herds in California stood at 186, by far the most of any state, according to USDA. Some 388 herds have been infected nationwide, according to USDA's count.
The rapid spread in California started Aug. 30, when the National Veterinary Services Laboratory confirmed infection in three dairies. The first known U.S. cattle case occurred in Texas back in March.
Steve Lyle, director of public affairs for the California Department of Food and Agriculture, said CDFA is testing herds via bulk tank samples, so an exact number of infected cows is not available.
He added that since the virus is new to cattle, the response is evolving as fresh information is confirmed. One dairy facility has been cleared since the first outbreak.
“Our initial detections were based on reporting of clinical signs,” he wrote to Agri-Pulse. “Now most of our detections are via proactive testing, and we are finding dairies before the cows get visibly sick.”
Lyle said CDFA is "monitoring closely" to see if infection can jump from cattle back to birds, but there's no current evidence of that happening.
Steven Fenaroli, a policy advocate with the California Farm Bureau, said the group has been very happy with the government response so far.
“CDFA and USDA have done a great job even before H5N1 was found in California in coming up with contingency plans and pulling stakeholders including CAFB together to make sure that anything proposed was appropriate for California’s farmers and ranchers,” he told Agri-Pulse in a statement. “We have regular meetings and updates from them, and even amid the uncertainty of the virus, they continue to be incredibly responsive, and do everything possible to limit the impact.”
Cut through the clutter! We deliver the news you need to stay informed about farm, food and rural issues. Sign up for a FREE month of Agri-Pulse here.
Western United Dairies CEO Anja Raudabaugh agrees with Fenaroli, though she expressed concern for the financial losses facing Central Valley farmers.
Anja Raudabaugh“It has been hard on the farmers who are placed under quarantine, and financial relief for those dairies who have had a lot of mortality and milk production losses is not compensable to the milk losses we’re seeing,” she wrote to Agri-Pulse, adding she was unsure that many affected farms could make it back to full production within the next several months.
Despite early October’s heat wave, which Raudabaugh said was a setback for cows in recovery, she said the current cool down in temperatures across the state is already making a difference.
During an Oct. 24 press call addressing federal cooperation with states experiencing H5N1 outbreaks, Eric Deeble, USDA's deputy undersecretary for marketing and regulatory programs, confirmed that anecdotal reports of increased mortality rates among infected herds are likely due to excessive heat, in addition to farm-to-farm management differences and the proximity of infected cattle to one another.
USDA sent five staff members to support CDFA traceback and epidemiological investigations and nine case managers to complete questionnaires and follow up on contact traces. They also require testing of all lactating cows prior to interstate transport.
CDFA confirmed 16 human cases Monday; all the people had contact with infected farm animals and are experiencing only mild symptoms.
Nirav ShahPhil Durst, a field-based educator with Michigan State University Extension who published an article detailing what has been learned about HPAI infections in dairy cattle since March, said the incidence rate peaks between four to six days after the first cow is infected. Older cows are more likely to be infected, though most recover and entire herds can recover within weeks.
“Farms have reported some abortions (likely due to high fever), some increased culling and certainly higher labor and veterinary costs,” Durst wrote, estimating $200,000 in financial losses for a 1,000-cow herd.
Some of the unknowns Durst listed include the primary cause of spread, how long an immune response will hold off reinfection, and why older and lactating cows are more likely affected. He wrote that voluntary contact with a dairy’s veterinarian is always the best first response for a farmer who thinks their cattle may be infected, as the vet can report it quickly to their state’s department of agriculture.
Since Sept.19, three new outbreaks in commercial poultry units have occurred in California. Bill Mattos, president of the California Poultry Federation, told Agri-Pulse he’s on high alert due to their proximity to dairy operations.
“The outbreak was a lot more aggressive early in the year as it moved all around the United States,” Mattos said. “And right now, we're pretty biosecure, and we're trying to keep our premises locked down.”
For more news, go to Agri-Pulse.com.
