DES MOINES, Iowa—As the U.S. dairy industry confronts a bird flu outbreak, with cases reported at dozens of farms and the disease spreading to people, the egg industry could serve as an example of how to slow the disease but also shows how difficult it can be to eradicate the virus.
There have been earlier bird flu outbreaks in the United States, but the current one started in February 2022 and has forced the slaughter of nearly 100 million chickens and turkeys. Hot spots still occur, but their frequency has dropped in part because of biosecurity efforts at farms and a coordinated approach between companies and agricultural officials, experts say.
How Can a 1,500-Pound Cow and a 5-Pound Chicken Have the Same Illness?
It’s commonly called bird flu because the disease is largely spread by wild birds that can survive infections. Many mammals have caught the illness too, including sea lions and skunks.Animals can be infected by eating an infected bird or by being exposed to environments where the virus is present. That said, there are big differences in how cows and chickens have fared after getting infected.
Bird flu is typically fatal to chickens and turkeys within days of an infection, leading to immediate mass killings of birds. That’s not true for cows.
Dairies in several states have reported having to kill infected animals because symptoms continued to linger and their milk production didn’t recover, but that’s not the norm, said Russ Daly, an extension veterinarian at South Dakota State University.
What Has the Egg Industry Done to Protect Chickens?
Egg operators have become clean freaks.To prevent the disease from spreading, egg producers require workers to shower and change into clean clothes before they enter a barn and shower again when they leave. They also frequently wash trucks and spray tires with solutions to kill off virus remnants.
Many egg operations even use lasers and install special fencing to discourage wild birds from stopping by for a visit.
“Gone is the day of the scarecrow,” said Emily Metz, president of the American Egg Board.
Without these efforts, the current outbreak would be much worse, said Jada Thompson, a University of Arkansas agriculture business professor. Still, maintaining such vigilance is difficult, even if the cost of allowing disease into an operation is so high, she said.
Can the Same Be Done to Protect Cows and Dairy Workers?
Yes and no.Dairies can certainly reduce the spread of disease by limiting access to barns, so people and equipment don’t bring in the virus from elsewhere. Workers could also wear eye protection, aprons, and gloves to try to protect themselves, but there’s no way around it: Big animals are messy.
“The parlor is a warm, humid place with lots of liquid flying around, whether it’s urine, feces, water because they’re spraying off areas. Cows might kick off a milk machine so you get milk splatter,” said Keith Poulsen, director of the Wisconsin Veterinary Laboratory.
Dairies also don’t have time or staff to disinfect milking equipment between animals, so equipment could become contaminated. Pasteurization kills bacteria and viruses in milk, making it safe for people to drink.
Mr. Poulsen said the dairy industry could follow a path laid by the poultry and pork industries and establish more formal, better funded research organizations so it could respond more quickly to problems like bird flu—or avoid them altogether.
The dairy industry also could tamp down disease spread by limiting the movement of lactating cows between states, Mr. Poulsen said.
The U.S. Department of Agriculture will soon begin testing a vaccine that could be given to calves.
The egg industry is also hopeful researchers can develop vaccines for poultry that could be quick, inexpensive, and effective. Workers can’t give shots to the millions of hens that might need a vaccine, but industry officials hope a vaccine could be distributed in the water the birds drink, in the pellets they eat, or even before birds hatch from their eggs.