When I wrote an article for Swine Line late last fall, we had just finished testing our transportation protocols at South Dakota State University (SDSU), and these protocols proved to be effective against PED virus. We were also in the process of testing our 3M filters to see if they would be successful in stopping the particles carrying PED virus. I am happy to report that the filter tests were successful.
Since last fall, however, we’ve seen the number of PED virus cases mushroom. Just in the last month, nine Pipestone System farms have identified cases of PED infection. As we investigated those infections, we became suspicious that feed was a potential route of transmission of the virus.
On the first day we saw sick pigs, we took samples from inside the feed storage bins at the infected farms. On four of those farms, we found the virus in bins containing feed for the areas of the barns that first became sick. We then tested the feed bins of farms that had not become infected, and they were negative for PEDv.
The strong positive correlation between PEDv in feed bins and areas of the farm that exhibited the illness led us to do two things.
- We conducted a bioassay to see if we could make pigs sick with feed from the PED-positive bins. Dr. Scott Dee conducted this trial at SDSU. The trial proved that pigs could be infected with feed from these bins.
- We also began a “Feed Mill Assessment” project, which involves visiting mills that produce and deliver feed to our pig farms and working with those mills to educate their staff on PED virus.
In the process, we’re learning about and providing information on best practices to reduce feed mill contamination. We’ve also begun to collect samples over time and test for PED virus. Our goal is to determine our biggest risk factors for PED contamination in the mills.
In short, we know one of the modes of transmission of this virus is through feed. We just don’t know how that is taking place. This story is changing monthly, weekly, daily…and sometimes hourly. Stay tuned for more breaking news.
In the meantime, continue to emphasize strong on-farm biosecurity practices. Continue to sanitize trailers. Contact your Pipestone veterinarian or your feed supplier if you have any questions about feed as a risk.