A new analysis by Iowa State University’s Derald Holtkamp shows porcine reproductive and respiratory syndrome (PRRS) caused an estimated $1.2 billion per year in lost production in the U.S. pork industry from 2016 to 2020, an 80% increase from a decade earlier.
Since the mid-1980s, this virus has been present in the U.S. swine herd and continues to be a major threat to the pork industry.
“After 40 years of experience fighting this virus, veterinarians and producers are still losing the battle against PRRS,” says Holtkamp, professor of veterinary diagnostic and production animal medicine.
He led the new research and a 2012 study that estimated the virus caused $664 million in annual losses from 2006 to 2010.
The sharp increase in economic damage caused by PRRS isn’t driven by changes in market prices, production cost or the size of the U.S. pig inventory, he explains in an Iowa State University release. Those factors only account for about $108 million of the $536 million increase in annual losses.
The other $428 million is attributed to the portion of herds affected by PRRS and the differences in productivity between affected and unaffected herds, he says.
Weekly herd disease status data gathered by a swine health reporting program at the University of Minnesota and productivity data collected from pork producers by Iowa State postdoctoral researcher and study co-author Henry Osemeke was used to determine this estimate. Holtkamp presented the study at the International Pig Veterinary Society Congress in Leipzig, Germany.
Larger Increase Than Expected
Although the increase was larger than Holtkamp expected, pork industry veterinarians who have seen the data aren’t surprised.
“Without fail they say, ‘Nope, that seems right,’” Holtkamp says.
He points out that these cost of disease studies are crucial for allocating research funding and informing industry decision-making as pig producers often plug these numbers into their formulas.
Biosecurity Makes a Difference
Controlling PRRS is a continuous challenge in part because the RNA virus that causes PRRS evolves frequently and vaccines have limited effectiveness.
“I’ve been doing this for going on 30 years now, and more than half a dozen times in my career we’ve thought we had things figured out and were on top of it,” Holtkamp says. “But this virus always finds a way. It outsmarts us every time.”
Of particular note, a disproportionate amount of the production loss increase came in herds of growing pigs, as opposed to breeding herds.
- In the 2006-10 study, growing herds accounted for 55% of lost production.
- In the new study, 68% of the estimated losses came from growing herds.
Holtkamp attributes this difference to new virus variants and changes in sow immunization methods.
As always, heightened biosecurity is key to reversing the effect of PRRS because industry consolidation and growth makes facilities more interconnected, increasing exposure, Holtkamp says in the release.
In addition, enhanced sanitation of livestock trailers and at facility entrances are common improvements, but every operation is different. Producers should devote resources to identifying their largest biosecurity gaps and most effective prevention measures, he encourages.
“It can be complicated, but it’s worth it to spend that time to find those risks,” Holtkamp says. “You don’t know if you don’t take the time to look.”
