The sign outside Rick Klaphake's turkey farm reads: "Absolutely no trespassing — disease control."
The 12,000 hens gobbling away in one of his 500-foot-long barns were living out the final days of their 18-week lives. But not because of bird flu. Most of them will grace holiday dining tables starting with Thanksgiving later this month.
Poultry growers like Klaphake, as well as government and industry officials, say they're confident the U.S. poultry industry is safe from dangerous strains of bird flu, such as H5N1, that have ravaged poultry in Asia and spread to parts of Europe. The biggest reason: the animals are kept in, and people and wild birds are kept out.
"We've taken steps to protect ourselves by confining the birds," Klaphake said.
Klaphake's operation is typical for turkey farms in Minnesota, the country's top turkey-producing state. And across the country, top chicken producers follow similar strategies for keeping their flocks free of disease.
On Klaphake's farm near Sauk Centre, turkeys have little human contact. Few visitors are allowed. Farm employees shower and change clothes before entering the barns, and wear disposable plastic booties to avoid tracking in germs. Automated systems feed and water the turkeys.
While the sides of the barn open to allow fresh air in, screens keep out migratory birds that could carry in bird flu. Exterminators make monthly visits to control rodents that might track the virus in.
The turkeys are moved into the barns when they're one day old and don't leave until they're trucked off to a nearby processing plant. They're watched closely for signs of illness, and blood samples from every flock are tested at the plant, said Klaphake, the president of the Minnesota Turkey Growers Association.
It's all very different from the way poultry is raised in Asia, where chickens and ducks run loose and live close to people and other livestock, and are sold live in open-air markets where they can infect each other and possibly people.
Like the $3 billion turkey industry, almost all U.S. chicken comes from big producers such as Tyson Foods Inc. and Perdue Farms Inc. that control everything from hatching chicks to marketing the finished products.
Bird flu is nothing new to these producers.
The viruses come in two groups: high pathogenicity, which are the deadliest kinds, and low pathogenicity, which cause less serious illnesses. The virus causing the most concern for birds and people in Asia, H5N1, is a high-path strain. The U.S. Department of Agriculture says there's no evidence that it has spread to people or animals in the United States. The last known outbreaks of high-path bird flu strains in the United States were a small one in Texas last year and in a large one that struck Pennsylvania and Virginia in 1983.
But the milder forms turn up often. Producers have tests to spot them, and those tests will also detect the more dangerous forms, said Dale Lauer, director of the state's poultry testing lab in Willmar.
Bird flu typically spreads from bird to bird through contact with their droppings or respiratory secretions. What worries health officials is the prospect that a dangerous strain could mutate into a version that could easily spread from human to human and kill millions.
The data show that bird flu among turkeys dropped dramatically as producers switched to confinement from open-range operations, Lauer said.
Other defenses are in place. The United States does not allow poultry imports from Southeast Asia, and it's monitoring migratory birds that might come into contact with Asian birds as they pass through Alaska. And bioterrorism defenses set up after the Sept. 11 attacks will help stop any spread of dangerous strains of bird flu, said Julie Craven, a spokeswoman for Willmar-based Jennie-O Turkey Store Inc., the country's largest processor.
But critics of large-scale farming aren't sold on what the big producers are doing.
Dr. Michael Greger, director of public health and animal agriculture for the Humane Society of the United States, said the biosecurity measures are important, but he maintained that the big confinement operations actually add to the danger of a global pandemic.
"I think they're overconfident in their ability to keep these bugs out," Greger said. "You can do your best, but unfortunately these bugs still get inside."
Having many hosts packed into small spaces gives flu viruses more opportunities to mutate, he said. On top of that, he said, the stress of living "beak to beak" weakens birds' immune systems.
The solution, Greger said, is to change the way poultry is raised, reducing stresses on the birds by giving them more space, cleaner conditions and protected access to the outdoors, plus better genetics, so they're better able to fight off infections. He said that would reduce the threat of bird flu viruses mutating into such virulent strains as H5N1.
Organic poultry producers are also concerned, but not enough to turn to big confinement operations, said George Siemon, CEO of the Organic Valley Family of Farms, a cooperative of 700 farms based in La Farge, Wis.
Organic Valley says its first line of defense is trying to raise healthier birds, and its growers closely monitor their flocks. If there were an outbreak nearby, its farmers would keep their chickens indoors, begin testing and take steps to reduce the risk of outside infection.
Siemon, whose own farm near La Crosse, Wis., includes about 3,600 egg-laying hens in two houses, said federal rules require that organic birds have access to the outdoors, and organic consumers expect it.
Research shows that organic animals of all sorts have stronger immune systems, Siemon said. He also said he hasn't had any problems with wild birds such as ducks flying down the Mississippi River flyway infecting his flocks.
"We've been having birds outside for 13 years," he said. "We haven't had any issues with any diseases from that."
Still, he said, organic producers will comply with any temporary or emergency standards the government might impose.
"When you get down to human health you can never be too concerned about this," he said.