In California, cows that died from bird flu are rotting while dairy farms wither in the heat

By Leah Douglas

(Reuters) – Cows are dying from bird flu at a much higher rate in California than in other affected states, industry and veterinary experts said, and some carcasses are rotting in the sun as rendering plants struggle to process all the dead animals.

Carcasses left outdoors and picked up by scavengers could encourage the spread of bird flu to other birds and wildlife, or deteriorate the carcasses to the point where they can no longer be processed for animal consumption, experts told Reuters.

Bird flu has spread to more than 300 dairy herds in 14 states this year, infecting 120 herds in the highest milk-producing state of California since late August. The virus has also infected 25 people this year, including 11 in California.

Infected flocks in California have mortality rates as high as 15% or 20%, compared with 2% in other states, said Keith Poulsen, a veterinarian and director of the Wisconsin Veterinary Diagnostic Laboratory who has researched bird flu.

The California Department of Food and Agriculture did not respond to questions about bird flu mortality rates.

In the state’s Central Valley, extreme heat has worsened health problems in cows suffering from the virus, causing fever, slowed milk production and other symptoms, said Anja Raudabaugh, CEO of Western United Dairies, which owns nearly 90% of the state’s dairy farms represents.

On farms that typically lose one or two cows a month, hundreds have died, Raudabaugh said.

Farmers contract with rendering companies to pick up dead cows. But rendering companies that process the carcasses into tallow and hides are struggling to keep up, leading some farmers to leave their cows outside for days, Raudabaugh added.

California Department of Agriculture spokesman Steve Lyle said the state’s rendering industry has capacity for the higher mortality rates and that a rendering company experienced delays this month due to higher temperatures.

Temperatures in the southern Central Valley, where many dairies are located, have exceeded 95 degrees Fahrenheit (35 degrees Celsius) six times so far in October, according to the National Weather Service.

Baker Commodities, a California rendering company, has seen an increase in dead dairy cows due to the heat and bird flu, said spokesman Jimmy Andreoli II.

The company’s routes have been slightly delayed due to safety measures, which include drivers disinfecting truck tires to avoid spreading bird flu from farm to farm, but it has managed to keep up with demand said Andreoli.

The state needs to do more testing to contain the virus, said Crystal Heath, a Los Angeles veterinarian who took photos of dead cows in front of the Mendonsa Dairy in Tulare County.

For safety reasons, farmers keep dead infected cows away from their healthy herds to reduce the risk of further spread, said Raudabaugh, whose organization represents Mendonsa Dairy. Mendonsa could not be reached for comment.

Joey Airoso, a Tulare County dairy farmer, said he is surrounded by dairies affected by bird flu infections.

“The way it’s traveled around here, I feel like almost everyone will probably understand it,” he said.

(Reporting by Leah Douglas in Washington, D.C.; Additional reporting by Tom Polansek in Chicago; Editing by Bill Berkrot)