Viral Pathogens Survive in Feed During 6,000-Mile Journey

( Jennifer Shike )

After 107 hours of transport over 6,000 miles, a new study confirms the survivability of three significant viral pathogens of pigs during an actual shipping event.  

For years, Scott Dee and his team at Pipestone Applied Research have been studying the risk of virus movement in feed. Early work completed in the laboratory confirmed the survivability of porcine epidemic diarrhea virus (PEDV) in feed as the vehicle for transmission and transport. 

His latest research demonstrates that the results discovered in the laboratory can be reproduced in real-world conditions. This study, working with funding provided by the Swine Health Information Center (SHIC), confirmed the ability of viable porcine reproductive and respiratory virus (PRRSV), Senecavirus A (SVA), and PEDV to be transmitted in both soy products, while viable SVA was recovered from all five of the tested feed ingredients. In contrast, survival was limited in the vitamins and amino acid ingredients.  

“We wanted to expose the viruses to as many environments as possible in the continental U.S.,” Dee explained in a SHIC release. “This was like an actual commercial journey.”

Feed was spiked with viruses loaded in containers on a truck and driven all around the U.S. The trip lasted 21 days, involved 107 hours of transport, crossed 14 states, and covered approximately 6,000 miles, Dee said. The truck journeyed from Minneapolis to Iowa and from Colorado to Texas, across the southern coast, up the eastern seaboard, and back to the Midwest. The virus-spiked feed was exposed to mountainous, western, gulf coast, eastern, and New England environments as well as Midwestern.

Feed samples were tested upon the truck’s return to Minnesota. SVA was found in every feed ingredient being evaluated, comparable to what was seen previously in the lab, Dee said. SVA – a surrogate of food-and-mouth disease – survives and is stable in feed ingredients. 

Meanwhile, PEDV and PRRS survived in feed as well, results showed. This demonstration confirmed lab results showing soy-based products being supportive of viruses; both organic and inorganic soybean meal were included and all viruses lived well in each, the release said. 

Dee stressed that this demonstration project was conducted with great care for the viruses included in the test ingredients. Samples were contained securely in boxes loaded in the trailer without risk for spills. There was no other cargo in the trailer and the only stops made were for fuel and overnight rest, the release said.

“We wanted to protect the sanctity of agriculture,” Dee explained. “These were not foreign animal diseases. We talked to the Board of Animal Health director and USDA. If we were managing the demonstration as described, they were perfectly fine with it.”

In addition, the amount of feed in this demonstration was only 30 grams per test. The small sample size made it possible to test the entire quantity of feed at the conclusion of the journey so there were no false negatives. 

Next up on Dee’s project list? A full-scale demonstration.

“We’re going to do this whole thing again in November, using one-ton totes of organic and inorganic soybean meal,” he said. “We will get away from the 30-gram amounts and into a representative volume that producers are dealing with all the time in tons.” 

Sample testing will be completed when the feed products returns from the journey which will utilize the same route and viruses. 

Dee wants to bridge the gap from lab to the real world. He believes the results will help people gain more confidence with evidence viruses can live in feed under a commercial shipping event, the release said.

More from Farm Journal's PORK:

Autogenous Streptococcus Suis Vaccine Protects Piglets


Never Surrender: Scott Dee Goes To Battle To Protect U.S. Swine Herd

Lessons Learned From PEDV Could Keep ASF Out of the U.S.

Can Feed Additives Reduce Viral Contamination of Feed?

PRRS: Deciphering the Mystery Disease


Antibiotic-Free Production Puts Pigs at Extreme Disease Risk