Looking at how viruses spread in feed, Dr. Scott Dee, Director of Applied Research at Pipestone Veterinary Services, has performed laboratory work to simulate feed travel across destinations to measure the vitality of viruses in feed over time. This time, he and his team conducted a real-world demonstration.

“We took PRRS, PEDV and Senecavirus and put them in one-ton totes - all together in a little ice cube and put that ice cube in a one-ton tote,” said Dee. "We put those totes of soybean meal and complete feed on a truck and drove it around the United States for 23 days - about 6,000 miles across 29 different states. We drove all around the Continental US to expose the viruses and the feed to various climates.”

From the experiment, Pipestone Veterinary Services learned that all three viruses survived the trip in the soy feed. In the complete feed, the PEDV and Senecavirus survived; the PRRS virus did not survive. To conclude the study, they fed the complete feed to pigs to show that PEDV and Seneca were still alive after the journey and pigs that ate that feed got sick. Pipestone Veterinary Services found the study was real-world evidence that feed and virus transmission can be a significant risk, and producers need to be careful with biosecurity in regards to feed.

African swine fever implications

The study hasn’t been performed directly with African swine fever (ASF) virus because of its high risk, but Dee says it's possible to draw conclusions from the study that can be applied to ASF, especially considering other ASF research that's been conducted. Laboratory work from Dr. Niederwerder’s laboratory from Kansas State University suggests that the virus has the capability of surviving for long periods of time in feed. In the lab, they found that ASF survived for over 30 days in feed.

“If ASF got into the US, it would fly around the US in contaminated feed,” said Dee. “That's the major take-home from this project. If Seneca and PRRS and PED can do it, ASF will certainly be able to do it too. We talk about controlling the initial outbreak and compartmentalizing. I think we've got to consider how the feed is going to play into that, not just pig movement, but feed movement. That's the real take home for producers - we better be careful with feed.”

What can producers do?

Pipestone Veterinary Services has looked at multiple routes producers can take to lower the feed risk. The feed additive approach allows producers to add a product to the pigs’ diet that has antiviral properties. Most products are made for nutritional purposes, but if it has an acid or formaldehyde, it can have the ability to destroy viruses.

“We tested, using Seneca, PRRS, and PEDV once again,” said Dee. “We can't do this with ASF. We showed that out of 15 different products that we tested, 14 of the 15 actually reduced the effect of the virus in feed. And pigs did extremely well when eating mitigated diets as compared to pigs eating non-mitigated diets, side by side. So we showed that a feed additive is a good thing, especially for viruses. There were significantly improved gains and reduced mortality in pigs that were on mitigated diets as compared to pigs that are on non-mitigated diets. Serious differences, 1% to 0% on the mitigated diet mortality, 10% on the non-mitigated diet mortality, so quite a striking difference.”