Producers unite against PRRS
PRRS is an ongoing issue for pork producers. An outbreak of porcine reproductive and respiratory syndrome, or PRRS, can devastate a hog farm. Brent Sandidge, of Ham Hill Farms near Marshall, knows this all too well. His farm was diagnosed May 1, 2010. The conditions were perfect for PRRS. “It was cool, damp, lots of mist in the air, light breezes,” Sandidge says. “PRRS just broke everywhere.”
It’s usually transferred through fluids or the air. Although it’s difficult to pinpoint where the outbreak started, he’s fairly certain it was carried into a finishing barn and became airborne. “We were marketing on April 15, and a truck of our market hogs turned over leaving the farm,” he says. “We broke several biosecurity rules over the next two hours, then tried to clean and disinfect everything in the next few hours.”
He tried to control the outbreak by shutting down. “We were being really successful. And then one pig showed up which was positive in July 2011,” he says. “So something didn’t hold.” He then took another measure. “We totally depopulated in September 2011, then repopulated,” he says. “When we did that, we got PRRS out of this area.”
In five weeks, he hauled off about 619,000 pounds of dead animals. His family has been in the hog business since his dad started in 1954. Now he raises 3,000 sows farrow to finish, and markets 60,000 a year plus 10,000 weaners. Since PRRS was discovered about 25 years ago, it was never a devastating problem here. “September 2011 was the first time there haven’t been pigs at Ham Hill in my lifetime.”
Afterward, he helped organize a PRRS control group of six area hog farmers, along with a local feed dealer, veterinarian Dr. Scott Pfizenmaier, Boehringer Ingelheim, and Cargill Pork, which also had an outbreak. “I can’t say enough about Cargill and all they did,” he says. “There was an incentive to get the area negative.”
Someone to get the word out
Coordinators are crucial for sharing information. For this group, it was former University of Missouri Extension veterinary specialist Beth Young.
This group has paid off. “We’ve diverted some PRRS-positive pigs from coming into the area,” Sandidge says.
At the 2012 University of Missouri Swine Institute, Young explained that groups work to eliminate or control PRRS in the area, after testing the herd. In this case, all sites are now PRRS-negative. “So far, we’ve got a great group of producers,” Young says. “Nobody has come out and said, ‘No, we don’t want to participate.’ ” Due to the lack of cases, she says it was easier to eradicate the virus. “Elimination makes a lot of sense.”
Veterinarian Dr. Paul Yeske of the Swine Vet Center in St. Peter, Minn., also spoke at the event. “We lose $1.8 million everyday as an industry due to PRRS,” Yeske says. He mentions testing methods like using oral fluid with a hanging rope in finishing barns and nurseries. Another is the “Swiffer test,” often used for trucks and flooring. This makes testing easier and increases likelihood of surveillance on grow-finish sites, so statuses can be known for sure. Knowing virus status of sites is key to the success of control or elimination projects.
Sandidge notes three keys to biosecurity. Pigs are most important. “You definitely test any incoming pigs,” he says. “You have to have good isolation procedures and know the status of the farms those pigs are coming from.”
Next is transportation. On Sandidge’s farm, trucks are cleaned regularly in the wash bay. “When truck drivers come here to haul market hogs, we have transfer stations,” he says. “They change into our clothes and boots when they enter our transfer station. We never go where our truckers go.” Employees are last. This is important to consider when changing locations. “You have to have downtime if you’ve been to another farm.”
PRRS has become more severe over time. New strains are something to watch out for. “It seems like it just keeps mutating and staying one step ahead of us.” So, it’s important keep updated on what’s going on in the area. “One of the things you want to do is know farm statuses,” he adds.
One solution in pig-dense areas is modified live vaccines, especially in grow-finish populations to help reduce clinical effects of PRRS and help reduce the shedding of PRRS into the area. Producers should know vaccination doesn’t completely eliminate it. Similar to flu shots, these vaccines reduce impact, says Dr. Paul Yeske of the Swine Vet Center in St. Peter, Minn. The shedding period is 70 or more days when pigs aren’t vaccinated, vs. 45 days when they are vaccinated.
Certain biosecurity practices are necessary before installing filter systems, which are expensive and require more attention to detail. However, they provide great biosecurity by controlling the air — what Yeske calls “farming in a bubble.” These filtered sites aren’t perfect, but are significantly improved over the site’s history, and are often used in high-risk areas.
Herd closure is an effective way to eliminate PRRS. It requires closing the herd to new introduction for 210 days once totally infected, then avoiding cross-contamination of litters by limiting cross-fostering and piglet movement, and being careful with anything used between litters. Yeske notes producers should watch hallways, often the most infected areas. “If you’re in a herd closure, you had better think about washing the hallways.”
Bench-entry systems are useful, separating dirty and clean areas with benches. “I’m really of fan of these bench systems,” Yeske says. These work well in grow-finish sites where showering isn’t as easy to set up, and employees might visit multiple sites in a day. “That helps reduce that tracking into the farm, even if there is a shower area.”
PRRS PREVENTION: Brent Sandidge of Ham Hill Farms, near Marshall, helped organize the area’s control group, which he says has paid off. “We’ve diverted some PRRS-positive pigs from coming into the area,” Sandidge says. Communication is critical to these groups. “It’s amazing how few people you need to contact, and you can have the area pretty well covered.”
WASH BAY: Sandidge says an important step in PRRS control is monitoring transportation to prevent spreading PRRS or contracting it. At Ham Hill, trucks are cleaned regularly in the wash bay. “When truck drivers come here to haul market hogs, we have transfer stations,” he says. “They change into our clothes and boots when they enter our transfer station. We never go where our truckers go.”
This article published in the January, 2013 editionof MISSOURI RURALIST.
Swine Herd Management