Pork producers gain ground against PRRS with reduced production losses
Porcine reproductive and respiratory syndrome (PRRS) remains one of the most costly viruses infecting US herds. But an Iowa State University study showed the annual cost of PRRS dropped nearly $100 million in 6 years since 2010 when PRRS was at full force.
The virus still extracts $580 million annually from producers, or $5 per pig for every hog slaughtered in the US. But vets and producers have gained ground controlling the virus early and reducing loss of production, according to Derald Holtkamp, DVM, MS, Iowa State University.
“In 2010, loss of productivity due to PRRS was $50 per sow. Now those costs are down comparable to negative,” Holtkamp said. “It’s a big shift and is related to how producers and veterinarians manage the transmission of viruses in herds.”
Reduced live-virus inoculation
Specifically, veterinarians and producers reduced the use of live-virus inoculation, Holtkamp told Pig Health Today.
The industry learned that herds naïve to PRRS experience greater production losses during an outbreak than herds testing positive prior to a PRRS outbreak. Naïve herds lost 2.5 pigs per sow per year more than positive herds.
“This led veterinarians and producers to opt for control rather than elimination,” he explained. “They continue to expose gilts before they come into a herd to either a live virus or a vaccine virus and maintain a level of immunity in the sow herd with a vaccine virus.”
The vaccination protocol has benefited sow herds with better reproduction, Holtkamp added.
Producers also learned PRRS-negative pigs at weaning will become positive before going to market. So now, most hog farms vaccinate PRRS-negative pigs at weaning to prevent lost production when pigs are introduced to the virus.
Biosecurity ground zero against PRRS
Heightened biosecurity also helped producers reduce PRRS’s adverse effects. “Pork producers made an intentional effort to improve biosecurity,” Holtkamp said. “It’s the No. 1 thing driving lower costs of PRRS.”
Stricter biosecurity used for PRRS helped the industry manage porcine epidemic diarrhea, he added. “PRRS probably forced us to do some things that are good production practices we wouldn’t be doing otherwise.”
While Holtkamp believes the industry is making progress against PRRS, he’s still cautious.
“More than once we thought we had PRRS figured out, but then the virus has an uncanny way of making us look foolish,” he said. “It really is a smart virus, unlike any other pathogen we’ve dealt with.”
Posted on December 8, 2017