Persistent PRRS Strains Pose Challenges for Pork Producers
Rumors of catastrophic porcine reproductive and respiratory syndrome (PRRS) outbreaks continue to shake the pork industry. One farmer told AgriTalk’s Chip Flory that he moved 1,500 pigs in and two-thirds of them were dead within a week due to PRRS.
There's no question that having to depopulate a sow herd and basically start all over is beyond devastating during a time of high inputs in the pork industry.
“Some of these strains are really tough to get out,” Paul Sundberg, DVM, executive director of the Swine Health Information Center, told Flory during AgriTalk on Thursday. “Some of these strains seem to persist longer than what we're used to and that means producers have to go to those kinds of extremes.”
But Sundberg says while some regions are experiencing more activity, PRRS incidence may not be that severe throughout the region. He says how bad it is depends on where your swine farm is located right now.
“Overall, the winter of 2021 to 2022, looks a lot like the winter of 2020 to 2021,” Sundberg says. “But we have regional outbreaks that are going on this spring. Those outbreaks make it look like cumulatively, we may be over what we were last year as far as PRRS outbreaks go.”
Sundberg says PRRS virus is unique because it’s easily spread by aerosol.
“There's a couple of factors that you have to keep in mind with that. When you get a PRRS break on a finishing floor, there's a cloud of virus that comes out of that site. That is a risk to any breeding herd in the area,” he says. “In comparison, if a breeding herd would break, it might not produce that cloud the way that a finishing floor does because of the way that facilities are built.”
Facility design certainly plays a factor in how this virus moves around, he adds.
Although he can’t say how much of a bite PRRS has taken out of this first quarter crop of pigs in 2022, Sundberg did say that states like Nebraska, Missouri, Illinois and Indiana, are all having more outbreaks now than what their usual baseline is. And the variants differ from region to region, too.
“Iowa and Minnesota have the 1-4-4 variant and that's a different variant than what's being found in Indiana, Illinois and Ohio,” Sundberg says. “If you get this, 1-4-4 and 1-7-4 can be very serious and cause bad outbreaks on individual farms.”
The April Domestic Disease Monitoring Report shows that there was increased activity of PRRS virus at a regional level in some areas such as Missouri, Nebraska, Illinois and Indiana.
The Swine Disease Reporting System advisory group reminds producers to keep working in improving biosecurity practices in breeding and especially in growing sites. Strategic usage of PRRS virus vaccination of growing pigs and pig placement could be potential tools to help contain the spread of PRRS virus and reduce the odds of a new spring wave of PRRS virus activity as seen in 2021.
"The best way for producers to prevent those types of losses is to be aware of what is going on around them. Talk to each other and to veterinarians. If there’s any PRRS outbreak around a farm, severe or not so much, do whatever possible to tighten up biosecurity on the farm," Sundberg says.
More from Farm Journal's PORK:
PRRS Strain 1-4-4: The Most Dramatic Strain I’ve Seen, Yeske Says
Naïve or Not? The Never-Ending Dilemma of Sow Farm PRRS Status
PRRS: Deciphering the Mystery Disease
PRRS Beyond 2020: The Fight Isn’t Over
Researchers Look for Ways to Control PRRS Via the Microbiome