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 |
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.“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.”
“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 swinehealth.org.
In an effort to examine the role of ingredients, especially vitamins, in feed biosecurity, the Swine Health Information Center (SHIC) and the University of Minnesota organized a vitamin manufacturing sector-wide workshop. Representatives from pork industry organizations including the National Pork Board, National Pork Producers Council, American Association of Swine Veterinarians, vitamin manufacturers and blenders, and feed industry associations joined SHIC and the University of Minnesota for the workshop in late April in St. Paul, Minnesota. Participants focused on vitamins and the processes involved prior to delivery to a producer’s farm, with special focus on African swine fever transport and transmission risk.
The workshop was convened to look at vitamins and premixes produced in areas of the world that have diseases foreign to the US that might pose a risk to US pig health if imported. One of the points of discussion of the workshop was about quality control procedures for both human and animal grade vitamins. It was pointed out that manufacturing plants are generally dedicated facilities in urban areas with third party certification programs in place.
Packaging and delivery of these vitamins in the US was explored and participants learned most are shipped in a raw state and blended in the US. Shipments are in sealed containers and in the chain’s custody for over 80 days before mixing into a feed ration. One area of concern is choline chloride which is blended with ground corn cobs and needs further investigation regarding its risk to the US herd.
The group recommended producers should know their suppliers. A Feed Ingredient Safety resource with a decision tree and feed-related questions is available on the SHIC website. Asking a few simple questions about their ingredients may help screen suppliers. These questions will identify legitimate manufacturers and blenders and help weed out the brokers or traders who do not know their sources or the procedures used to safeguard quality.
More details from the workshop and questions for further research and discovery can be found in these notes.
The Swine Health Information Center’s Domestic Swine Disease Monitoring Report for May 2019 shows PRRSV activity remained within the predicted values for 2019 to date. The level of detection of PEDV by PCR was within expected values for April with a 3 percentage point drop in positive results from March to April this year. PDCoV detection level was above expected in mid-April and Monitoring Report advisors said some sow farms experiencing outbreaks had clinical signs of the virus. Streptoccoccus suis (S. suis) continues to be the major agent detected on CNS tissue, however, in March and April there were an increased number of Pestivirus, Porcine Sapelovirus, and salt intoxication detections on CNS tissue when compared to the same time frame in 2018 and 2017. There was also an increase in detection of the following respiratory insultants this spring compared to 2018: Haemophilus parasuis, Actinobacillus pleuropneumoniae, Pasteurella multocida, and Mycoplasma hyorhinis.
In the Swine Health Information Center’s May Global Swine Disease Monitoring Report, the first African swine fever (ASF) outbreak in Cambodia is detailed as well as the continuing expansion in China where all geographical regions have now been impacted by the disease. Notes on USDA’s action to license an ASF vaccine are included in the Report as well as a summary of an Aujeszky’s disease outbreak in France. Classical swine fever presence and spread in Brazil and Japan are also discussed.
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