DES MOINES, Iowa – Porcine reproductive and respiratory syndrome (PRRS) costs the US pork industry $641 million per year, or $1.8 million per day or $114.71 per sow annually, estimates a new study underwritten by the Pork Checkoff and conducted by Iowa State University. The 2005 economic study calculated PRRS losses at $560 million annually.

"This Checkoff-funded work offers producers, veterinarians and every part of the pork chain a new and valuable insight into the economic impact of PRRS and underscores why we've leveraged domestic and international government funds to offer producers tools for regional control of this virus,” said Everett Forkner, National Pork Board president.

The 2011 study differed most the 2005 study in the allocation of losses between the breeding and the growing pig herds. Losses in the growing pig herd accounted for 88 percent of the total cost of PRRS in the 2005 study compared with 55 percent in the current analysis.

Derald Holtkamp, Iowa State University veterinarian, and agricultural economist Jim Kliebenstein collaborated on the study with others in academia, swine veterinarians in private practice and the US Department of Agriculture. Differences between the 2005 and the 2011 studies may be due to changes in the prevalence of PRRS virus and incidence of outbreaks, production and animal health management practices, inflation (accounts for 40 percent of the increase) and other pathogens that have emerged since 2005, such as porcine circovirus, they said.

Much of the data from the new study was collected from cooperating producers and veterinarians throughout the US in late 2010. Although not benchmarked in 2005, additional PRRS-related costs that producers must contend with, such as veterinary and biosecurity measures, were collected in this study. Researchers found these costs added $477.79 million annually to total PRRS costs, putting the cumulative cost of the disease at more than $1 billion per year when added to production-related losses.

The study's researchers were able to estimate additional PRRS statistics, based upon a survey of swine veterinarians from across the US. They found 28 percent of sows and gilts used for breeding in the US were PRRS virus-free and 60 percent of weaned pigs were PRRS-negative at placement.

"This study also confirmed conventional wisdom that says outbreaks in PRRS virus-free herds are more severe than outbreaks in PRRS virus-infected herds," Holtkamp said. "When comparing elimination methods, we found that the time required for herds to provide a return on investment was still relatively short with herd closure and rollover. However, we found that complete depopulation/repopulation appears to make economic sense only if there are other reasons to depopulate the herd or for high-value genetics herds."

The full report will be available in the coming months on