'PRRS puzzle may soon be solved
I think we're almost at the end of the trail'
By Laura Theobald
MINNEAPOLIS -- The missing piece of the PRRS puzzle is about to be discovered, researchers say.
According to Scott Dee, associate professor at the University of Minnesota college of veterinary medicine, solving how the virus spreads through air currents, and what can be done about it, is possibly just months away.
Dee spoke Jan. 20 at the Minnesota Pork Congress in Minneapolis.
"I think we're almost at the end of the trail," he said.
So far, Dee said, research has determined two ways that hogs can contract the Porcine Respiratory and Reproductive Syndrome virus. Transportation is a big risk -- the disease can linger in trailers where hogs can contract it. Insects are also a problem, as flies and mosquitoes can bite an infected pig and pass the virus to another.
But what producers really want to know, Dee said, is how to protect against the disease.
Three precautions can be taken when transporting swine. Trailer-baking is one option, which heats the trailer before transporting livestock to kill the virus. Another option is spraying disinfectant in the trailer -- and there are a number of ones that work out there, Dee said. A third method is thermal-assisted drying, which airs out trailers.
To protect against insect bites, Dee tested insecticides and screens that block insect entry into swine housing. The best results came with a combination of the two.
"Not only do these screens help in reducing the number of bites per pig, they do not harm the environment," he said.
"We've identified the important routes and ways animals are infected," Dee said. "Now we're looking at ways to control (it)."
Dee will be working on that final piece of the puzzle in the next few months, trying to nail down protection against airborne PRRS. He believes a filtration system might be the key, he said, something that hasn't surfaced in the United States yet but has on a few farms in France and Quebec.
"This is the future of swine biosecurity," Dee said. He himself had completely dismissed the idea of filters until he did the studies.
The filtration system is expensive, he said; it requires retro-fitting the barn or housing where hogs are kept. Another drawback: As yet there is no scientific evidence it will work.
"My role is to scientifically validate that," he said.
But Dee appears confident that is only a matter of time.
"We work fast," he said. "Then it's up to you and your vet to make it work on your farm."