Feed can transmit Porcine Reproductive and Respiratory Syndrome (PRRS) virus, writes veterinarian Dr. Scott Dee of Pipestone Applied Research in a report of his investigation at a customer farm.
The client practiced strict biosecurity, yet had an outbreak, so shut down his automatic feeder and called Dee who took samples discovering that there was PRRS in the feed.
The sow farm manager was doing everything right from a biosecurity standpoint. The barn was filtered. The farm team adhered to strict mechanical biosecurity protocols for trucks, people, supplies – basically everything you could imagine. The farm had a clean source for animals and semen.
Dee said “It reminded me of the first porcine epidemic diarrhea (PED) case back in January 2014 when we took paint rollers and collected all the interior leftover material in the bin.”
“It's really fortuitous that the manager called me, shut off the line and preserved the sample so I could sample the bin of feed that these index cases were consuming,” Dee points out.
“In our research on the susceptibility of viruses to survive in feed, we've kind of neglected PRRS virus,” Dee told reporter Jennifer Shike.
“Many years ago, PRRS was shown not to survive in feed at all.
"However, at the time of this study, they used a very insensitive laboratory test called virus isolation. PCRs and bioassays didn't exist. Still, everyone kind of wrote it off.”
“I can’t say PRRS transmission through feed is a major risk. But I think it's a big enough risk that we should talk about it. We've always wondered if it was possible that feed could bring it in,” he said.
The problem with figuring out the transmission of virus in feed in a farm setting is that the feed gets eaten and new feed comes in, Dee said.
“It's the first proof that PRRS virus can be alive in feed and can be transmitted through consumption of feed. That’s never been discovered before,” Dee said.
