Rising losses from PRRS are costing U.S. pork producers $1.2 billion a year

The viral disease has been present in U.S. swine herds since the mid-1980s and remains a growing threat, said Derald Holtkamp, ​​professor of veterinary diagnostics and animal husbandry.

“After 40 years of experience fighting this virus, veterinarians and producers are still losing the battle against PRRS,” said Holtkamp, ​​who led the new study and a 2012 study that estimated the virus caused $664 million in annual losses from 2006 to 2010 .

Data critical for manufacturers

The dramatic increase in economic damage caused by PRRS is not due to changes in market prices, production costs, or the size of the U.S. hog population. Those factors accounted for only about $108 million of the $536 million increase in annual losses, Holtkamp said. The remaining $428 million relates to the proportion of herds affected by PRRS and differences in performance between affected and unaffected herds.

The new estimate is based on weekly herd disease status data collected by the Swine Health Reporting Program at the University of Minnesota and performance data collected from pork producers by Iowa doctor and study co-author Henry Ozemeke. Holtkamp presented the research this summer at the International Society of Porcine Veterinary Science congress in Leipzig, Germany .

The cost of disease research is critical to allocating research funding and informing industry decisions, he said. “This is fundamental data for large manufacturers who plug these numbers into their formulas,” he said.

Biosecurity needs to be improved

PRRS is the most economically devastating disease for pork producers, causing respiratory distress in pigs of all ages and reproductive problems in breeding stock. Controlling the disease is an ongoing challenge, in part because the RNA virus that causes PRRS evolves frequently and vaccines have limited effectiveness.

“I’ve been doing this for 30 years, and more than a half-dozen times in my career we thought we had it all figured out and got it done,” Holtkamp said. “But this virus always finds a way out. He outwitted us."

A disproportionate share of the increase in production losses occurred in growing hog herds rather than in breeding herds. In a 2006–2010 study, growing herds accounted for 55% of production losses. In the new study, 68% of the estimated losses were in growing herds. Holtkamp attributed this to new variants of the virus and changes in sow immunization practices.

Improving biosecurity is essential to reversing the growing impact of PRRS as industry consolidation and growth make facilities more interconnected, increasing exposure, said Holtkamp, ​​a swine disease expert who often conducts outbreak investigations. Improving sanitation in livestock trailers and facility entrances are common improvements, but every operation must be improved. Manufacturers must devote resources to identifying their biggest biosafety gaps and the most effective prevention measures, he said.