With research confirming that swine viruses can be transmitted through feed and feedstuffs, new studies are looking at how to prevent the spread of foreign animal diseases, such as African swine fever (ASF), via these vehicles. Based on new research, the Swine Health Information Center (SHIC), the National Pork Board, the National Pork Producers Council and the American Association of Swine Veterinarians have revised the information for feed holding times.
The Institute for Feed Education and Research (IFEEDER), the public charity of the American Feed Industry Association, helped fund the research that resulted in the updated information that provide the best and most current understanding of viral survivability in feedstuffs and details for mitigating risk to domestic herds.
"The science on viral transmission through feed and feedstuffs is still relatively young, but it has yielded some interesting and potentially useful information on mitigating the spread of costly viruses, such as ASF," said Paul Sundberg, DVM, Swine Health Information Center executive director. "This includes recognition that not all imported feedstuffs are manufactured and handled in the same way. It’s important to know whether ingredients are produced under biosecure conditions and how they were shipped."
The new details decrease holding times over the initial estimations, which were calculated in October 2018 based on the available research, and give additional assurances of further viral degradation if the feed ingredients are contaminated.
"Variations of the same feed components might cause disparity in holding time confidence," said David Pyburn, DVM, National Pork Board senior vice president, science and technology. "For example, according to research using Senecavirus A (Seneca Valley virus), which is suggested to have the longest holding time of studied viruses, increasing holding times by an additional 30% would give an opportunity for 99.999% degradation of contaminating viruses."
More research would be needed to confirm that the results could be extrapolated to other feed ingredients in like classes to those studied. The updated information shows new holding times details for general informational and educational purposes. They should not be considered as to be recommending or advocating any specific course of action.
| Mean Holding Time for 99.99% Degradation | Days at 4°C (36.9°F) | Days at 15°C (59°F) | Days at 30°C (86°F) |
|---|---|---|---|
| Conventional Soybean Meal | 143 | 52 | 26 |
| DDGs | 494 | 182 | 26 |
| Vitamin D | 39 | 26 | 26 |
| Lysine | 78 | 13 | 13 |
“Continued diligence on feedstuffs origin, the manufacturing processes, the shipping methods and ‘born on date’ is essential,” Liz Wagstrom, DVM, National Pork Producers Council chief veterinarian, said. “Feedstuffs manufactured, sealed, handled, and shipped under biosecure conditions produces an ingredient free of pathogens and reduces the risk of post-processing contamination, resulting in little to no risk to animal health.”
For example, vitamins and amino acids are typically shipped in sealed or secure containers. Anything produced under unknown conditions or unsealed can pose an animal health risk. Imported soybean meal and DDGS are often transported in non-sealed or non-secure containers. Knowing the origin of ingredients and the disease status of the region or country is essential.
"The feed industry is a committed partner in the effort to prevent foreign animal diseases from entering the U.S. through imported feed ingredients," said Leah Wilkinson, vice president for public policy and education for the American Feed Industry Association. "This additional information on holding times is helpful. We encourage dialogue with your feed ingredient or feed supplier to discover all of the measures that have been put in place to supply a safe product."
Complete information on the research leading to the holding time calculation and the document, U.S. Pork Industry Organization Provide ‘Options’ for Handling Imported Feed Ingredients, are available at http://www.swinehealth.org.
Funded by America’s pork producers to protect and enhance the health of the US swine herd, SHIC focuses its efforts on prevention, preparedness, and response. As a conduit of information and research, SHIC encourages sharing of its publications and research for the benefit of swine health. Forward, reprint, and quote SHIC material freely. For more information, visit http://www.swinehealth.org or contact Dr. Paul Sundberg at psundberg@swinehealth.org.