Swine disease strikes UW-River Falls farm; annual auction canceled

A swine disease has broken out at Mann Valley Farm, one of the two laboratory farms run by UW-River Falls, causing the death of half the piglets.

Symptoms of Porcine Reproductive and Respiratory Syndrome, or PRRS, were first recognized at the Mann Valley Farm in November, but reproductive problems didn’t occur until recently with stillborn piglets. A positive diagnosis was confirmed on Feb. 2 and reconfirmed on Feb. 10, according to Justin Luther, interim chair and associate professor of reproductive physiology.

PRRS was recognized in the United States in the 1980s and affects 60 to 70 percent of swine herds. The disease causes elevated body temperature, loss of appetite, reduced growth, coughing, respiratory problems and reproductive issues. This can cause stillbirths and death of the fetus during pregnancy. Piglets that are born weak can have a mortality rate of 60 percent, while premature piglets can experience almost 100 percent mortality, according to a PRRS Fact Sheet for Animal Science published by North Carolina State University.

PRRS is currently restricted to the newly weaned piglets at the Mann Valley Farm, with about half of the piglets in the litters dying, according to Harry Larsen, manager at the Mann Valley Farm. The swine herd includes about 70 sows and, before the disease took hold, had about 150 piglets.

The virus cannot be contracted by humans or other animals, and is mainly transmitted through nose-to-nose contact between pigs. Although PRRS is not highly contagious, students who attend classes at the Mann Valley Farm and who may also be exposed to other herds of pigs are being instructed to use footwear that is specific to the farm and to disinfect footwear and clothes after contact, according to Luther.

Two ways to manage the PRRS are depopulation and managing through vaccination. Depopulation would mean getting rid of the current herd and re-introducing a new herd to the farm. Although what to do is still being discussed, Luther said that it will be more practical to look at vaccination and treating the pigs rather than depopulation.

“The reason we’re probably leaning more towards managing the disease at this particular stage is because we don’t have bio-secure facilities,” Luther said. “So who’s to say even if we did depopulate and repopulate, that we wouldn’t come up with the disease again in a year or two or three years from now?”

Although it hasn’t been determined how the virus was contracted, Larsen said that a factor contributing to the outbreak includes the open facility policy that the Mann Valley Farm follows, in which students and members of the community are welcome into the buildings. However, Larsen said, the open facility policy is critical to the education of UWRF students.

“So many people benefit from the open door policy that we’ve had with the hogs,” Larsen said. “So in order to maintain the education that we have here it really has to be continued.”

When it comes to how PRRS might affect Falcon Foods production at the University, Luther said that because the virus is specific to swine there is no human concern when consuming meat from swine with PRRS. Students working for Falcon Foods produce meats and cheeses from raw products supplied in part by the lab farms.

“We will easily be able to meet the demand of Falcon Foods and meet the demands of the other buyers and supporters of our box pork sale that we have every year,” Luther said.

Although the virus will not affect Falcon Foods, it has caused the cancellation of the Annual Show Pig Auction to avoid spreading PRRS to other herds.

“On our end, it’s really tough to take,” Larsen said. “We’ve got a lot of money into breeding these sows to get the show pigs, to get some good quality stock to sell and we’ve put a lot into that end of it. We’re kind of getting the rug pulled out from underneath us in the process.”