Next month marks the three-year anniversary of the first case of Porcine Epidemic Diarrhea Virus (PEDV) entering the United States.
In 2013, the virus raged war on the pork industry and subsequently sent the scientific community scrambling to identify causes of PEDV and develop vaccines. Like other swine diseases that have threatened the industry, PEDV was a harsh reminder that biosecurity is a key component for maintaining a healthy and profitable operation.
National Pork Board’s Dr. Lisa Becton, a veterinarian and Director of Swine Health Information and Research, notes it was evident early on that biosecurity played a key role in the spread and control of PEDV.
“PEDV emphasized the need to secure U.S. ports of entry and explore the safety of products imported to the United States,” said Dr. Becton. “PEDV has opened our eyes regarding our daily biosecurity practices and reinforced the need for operations to have a biosecurity plan in place and the importance of adhering to it on a day-to-day basis.”
To date she says the initial source of how PEDV was introduced to the United States has not been pinpointed but many theories point to an international introduction from feed sources such as the feed itself or feed totes. “Feed was a distinctive risk,” she says. “Initial research conducted focused on PEDV’s survivability on trucks, its transfer from pig-to-pig, its ability to move on organic material and how to control its spread.”
Research – A Critical Factor in the PEDV Fight
Much research has been conducted since the virus’s outbreak in 2013 and more research is underway including long-term sow immunity, the effects of composting PEDV infected carcasses and the work to develop a vaccine that prevents the virus. Other studies have centered on the role feed plays in the transmission of PEDV.
Professor Jason Woodworth, swine nutritionist and research associate professor at Kansas State University in Manhattan, Kansas, has completed a study that explores how pelleting feed could destroy the virus.
“We discovered that, if feed and feed ingredients were contaminated with the virus, pelleting that feed at certain temperatures would destroy it,” said Woodworth. His team contaminated batches of feed with PEDV and then pelleted them at temperatures ranging from 155°F-195°F. Pelleting feed at those temperatures killed the existing virus thus proving the “pelleting step is a good critical control point that can help reduce the risk of cross-contamination of infected feed,” said Woodworth.
Since the completion of this study, Woodworth’s team has further researched the impact of feed pelleting temperatures by contaminating feed and pelleting it at various temperatures beginning at 100°F-160°F-. The result: 130°F- is the breaking point for the disease. “If feed is pelleted below that temperature, PEDV could survive in the feed and lead to infectivity,” said Dr. Woodworth.
Other work by Dr. Woodworth’s team has focused on feedmill biosecurity as a way to minimize PEDV and other pathogen risk. Other studies have explored feed sequencing, flushing and chemical mitigation as successful steps that should be included in feedmill biosecurity protocols as ways to mitigate and prevent pathogen cross-contamination.