Cold weather has gripped most swine-production areas, which means closer confinement and a greater risk of porcine reproductive and respiratory syndrome virus (PRRSv). To keep this common and costly disease in check, a leading PRRS expert recommends building on a strategy of vaccination and sound management practices.
“Even though PRRS is just one piece of the puzzle, it is a very economically important one,” said Daniel C.L. Linhares, DVM, assistant professor in the Veterinary Diagnostic Laboratory at Iowa State University. “PRRS alone causes a $2 to $20 loss per pig, depending on immune status and PRRS isolate. Thus, immunizing pigs to PRRS has obvious benefits when the risk of infection is considerable.”
The next step is to implement management procedures that minimize the risk of disease spreading within herds.
“Anti-PRRS biosecurity has been studied for three decades, and much is known about virus transmission between pigs and between herds,” Linhares said. “Minimizing pig movements and having strategies to minimize risk of virus introduction through people and supplies are the first things to cover, because those risk events happen frequently in the field.”
He refers to the following practices as the “low-hanging fruit” for PRRS protection.
- Stock density.
- Access to feed (pan coverage and linear feeder space per pig).
- Early pig care (identification and treatment of sick pigs, and making sure all pigs are start on diet as soon as possible after weaning).
- Prevention and treatment of other diseases.
Finally, remember to monitor and track herd health as a benchmark for future diagnosis and treatment.
“Producers are well aware that you cannot manage what you don’t measure,” Linhares said. “I would encourage the swine industry to keep track of PRRS through active surveillance. Oral fluids-based surveillance is easy, practical, cheap and reliable. Surveillance data allows producers to calculate and estimate return on investment on anti-PRRS biosecurity and/or immunological solutions.”
No single tactic – or all tactics combined – will completely prevent or control PRRS. However, they can reduce the risk of introducing or spreading the virus, as well as contracting a coinfection that makes things worse. In combination with an effective vaccination program, they can play an important role in keeping PRRS in check during winter and beyond.