By Mark Bienhoff

It’s been five years since the swine industry was rocked by the wide-reaching economic and emotional impact of porcine epidemic diarrhea virus. The outbreak was a wakeup call for producers, processors, regulators and consumers alike. Almost immediately, it shed light on crucial biosecurity and pathogen control vulnerabilities across the ag economy.

What have we learned as a result? The root cause of the 2013 PEDV outbreak was researched and traced to a likely source. Since then, we’ve continually learned more about how PEDV and similar pathogens could be introduced into our market, and most importantly, how we can be better prepared to prevent this from happening.

The global nature of the U.S. swine industry continues to drive sweeping changes in areas such as biosecurity, antibiotic usage and animal welfare. Likewise, the global nature of the market must be considered with emerging pathogen threats and how that relates to pork exports.

How diseases find way here
A recent publication by Scott Dee, director of swine research at Pipestone Veterinary Clinic, and a team of established researchers, titled “Survival of viral pathogens in animal feed ingredients under transboundary shipping models,” explores how potentially devastating pathogens can make their way from foreign markets to our doorstep, and the findings are staggering. 

The study looked at an array of viruses that have global significance and are proven market disruptors, including foot-and-mouth disease (FMD), classical swine fever (CSF), African swine fever (ASF) and porcine reproductive and respiratory syndrome (PRRS), among others. Many of these will sound familiar to even those far removed from the ag industry. Throughout the 1990s and into the early 2000s, FMD devastated markets from Taiwan to the United Kingdom, where in 2001 an outbreak resulted in the slaughter of 7 million animals. The United States has maintained an FMD- and CSF-free environment, but the PEDV outbreak demonstrates how quickly a powerful virus can spread and disrupt production.

From China to Iowa
Midway through the PEDV outbreak in the U.S., when the strain was identified as a match to known Chinese strain, it was considered that animal feed could serve as a transport vehicle for such a virus. And that consideration is exactly where Dee’s research took root. Dee’s team infected common feed ingredients and simulated the nearly 40-day journey from China to Des Moines, Iowa, ultimately learning that PEDV survived in five of those ingredients.

The next step was to test the survivability factor with a wider array of pathogens — all under high levels of biosecurity at South Dakota State University and Kansas State University labs. Feed ingredients that were considered included pet food, dried distillers grain and soybean meal, among others — and more than 1,200 samples were tested when all was said and done.

Virus survives in shipping container
Ultimately, the study showed that many viruses are capable of surviving in feed ingredients even on the long-haul trip from China to the U.S. The survival rate was dependent on the properties of each virus and the pairing of a virus with specific feed ingredients. But make no mistake, feed can be a vehicle for transcontinental transport of pathogens, and some ingredient combinations even enhanced the survivability of select viruses.

The standout of the group, however, was ASF, which was shown to survive even in the absence of “protection” from a feed ingredient carrier. Practically, that means ASF could survive a more than 30-day journey in an empty shipping container; now that’s food for thought and concern.

Strategies to control disease
This study will not be the last of its kind. It already has, and will continue to, spark conversation among industry leaders and stakeholders. Armed with this information, we must now focus resources and careful thought toward effective feed-based mitigation strategies. Using the transboundary model he has developed, Dee will most likely follow up with research demonstrating efficacy of various available mitigants.

Kemin Industries, based in the heart of swine country, has been a leader in pathogen control for decades. Kemin offers an array of products and technologies designed to clean up feed, water, litter and more. We know that keeping pathogens at bay is the first step to an effective on-farm biosecurity program.

Now is the time to be proactive and diligent. A new foreign animal disease threat may be lurking just around corner or across the globe.

Bienhoff, DVM, is the pathogen control team manager at Kemin Industries.