In May, the Swine Health Information Center (SHIC) shared information on a study being conducted by Pipestone Applied Research and South Dakota State University (SDSU) showing the potential for viruses to contaminate and survive in feed ingredients. SHIC is providing resources and funding for the work being done. Dr. Scott Dee, director of research at Pipestone Veterinary Services, said they have learned porcine reproductive and respiratory (PRRS) virus and other pathogens can survive a transpacific study model in both conventional soybean meal (SBM) and dried distillers grains (DDGs). The next step in this process is the mitigation phase as the researchers begin looking at different feed additives that could neutralize viruses contained in feed.
“It was very surprising,” Dr. Dee remarked. “The PRRS virus was thought to be very susceptible to drying and warm temperatures. Lo and behold, it lived through the 37-day simulation. It was so shocking we did it twice to be sure it was accurate. It was – we got the same outcome.” The study is based on a model simulating the transboundary movement of contaminated ingredients that was developed to identify possible risk combinations of viruses and feed ingredients.
Of the 11 viruses studied so far, six survived in conventional SBM. Dr. Dee said they also saw PRRS and Seneca Valley Virus survive in DDGs. “Some ingredients present more risk than others,” he observed. “Certain ingredients and certain viruses get along.” Their work is looking at conventional and organic SBM, soy oil cake, lysine, choline, vitamin D, DDGs, three kinds of pet food, natural pork sausage casings, as well as complete feed which is used as a control. They have found the right ingredient with the right virus is a potential vehicle for pathogen entry. Influenza, however, did not survive in any of the ingredients tested.
While early discussion on the issue of transmission included totes and containers as potential vehicles for viral entry, Dr. Dee said their work so far does not support the theory. “We also look to see if the virus can live in the container absent a feed metric to determine if the virus can survive the journey on the side of the container,” Dr. Dee explained. “None yet have survived in the absence of a feed ingredient. It seems a virus needs some kind of protective coating to stay alive.”
In addition to the original transpacific modeling study, Pipestone Applied Research is also beginning a SHIC-funded project with Kansas State University. They will run the survival study on African Swine Fever (ASF) live virus, a very serious foreign animal disease, at KSU’s biosafety level-3 laboratory. This expanded work simulates a transatlantic model.
Dr. Dee says ASF exists in eastern Europe and is moving to western Europe so their model originates in Poland, moves through France, across the Atlantic where it lands in New York City, and eventually makes it to Des Moines, Iowa. The study will begin in early July and conclude their work on the survival aspect of disease transmission via feed ingredients. The intent is to repeat the transpacific model with high risk combinations of ingredients and viruses including PRRSv and PEDv in conventional SBM and Seneca Valley Virus in lysine.
The next step in this process is the mitigation phase as the researchers at Pipestone Applied Research and SDSU begin looking at different feed additives that could neutralize viruses contained in feed. “We will be looking at different feed additives,” Dr. Dee stated. “We will treat the feed with a mitigant and see what it does. Does it kill it right away or does it slowly degrade? Then we might have a solution and something we can do at the country of origin or at a mill in the United States. It’s the logical next step and will be interesting to see which products, we are testing nine, have a higher level of efficacy as far as neutralizing virus in feed.” Dr. Dee said this research is essential to develop protocols not currently understood.
A SHIC session is being organized for the Leman Conference in September at the University of Minnesota. The agenda for the session will include discussions of all the survival and mitigation studies being conducted on feed transmission.
The Swine Health Information Center (SHIC) asked Dan Sutherland, a swine industry veteran with years of experience in secondary marketing, to write a review of this process. Ongoing outbreaks of Senecavirus A (SVA or Seneca Valley Virus) continue to tax the resources of producers and their veterinarians, state and federal animal health officials, and sow and pig markets as each incident demands investigation to confirm it is not Foot and Mount Disease. The goal of the SHIC funded review was to gather information on the scope of these markets for better surveillance, biocontainment, and other risk mitigation protocols for the future.
Biosecurity and biocontainment have become standard protocols on swine farms as threats of emerging and foreign animal diseases have impacted production. For all the progress made, gaps still exist within production and marketing systems creating concern for individual producers and the national herd.
Sutherland said biosecurity and biocontainment can be difficult in secondary market. Trucks, animals, and people flow in and out of these markets, opening channels for disease transmission. Producers ship to the cull market using the most efficient and convenient timing and methods for their staff and transportation options, sometimes sacrificing biosecurity in the process.
The relatively low number of animals in the secondary market means animals can stay at buying stations or collection points for as long as a week when buyers are seeking a large enough group of similar pigs to fill an order. Though a buyer’s goal is to have the pigs at these points for as short as time as possible, reality is the collection of animals can become a concern.
Most culls and secondary market pigs are sold through a dealer network. Their mission is gathering the numbers needed to efficiently market hogs into many different channels within each category. Dealer networks vary in location and can be a significant distance from the farm so transportation time becomes an issue. In high hog density regions, fewer stations may be needed. When production is more remote, more drop-off points are required to collect the number of animals necessary to fill orders. In some cases, hogs may move 1,500 miles or more to get to market.
A challenge is animal tracking because, in the event of disease outbreak, needed information must be available. USDA requires sow and boar identification. An ear tag system lists only premises identification numbers and cannot be removed until the animal passes post mortem inspection.
The challenges of the secondary market are clear and with greater understanding of the channels, SHIC hopes to improve management of disease transmission and identify risks associated with foreign animal disease outbreak in these animals.
The entire Sutherland review can be read here. Sutherland spent a decade as an order buyer/dealer and 34 years as a packer buyer in a system including auctions and private buying stations for the secondary market.
In 1999, the Swine Futures Project identified emerging animal diseases as an area needing more attention. While the need was clear, no one worked toward an industry-led, coordinated response solution until recently. In June, representatives of the Swine Health Information Center (SHIC), National Pork Board (NPB), National Pork Producers Council (NPPC), American Association of Swine Veterinarians (AASV), USDA, state animal health officials (SAHOs), and producers for the first meeting of the Swine Disease Response Council (SDRC) to fill this need.
While some regulated diseases such as Foot and Mouth Disease, Classical Swine Fever, Pseudorabies and African Swine Fever have a regulatory process for response, unregulated emerging diseases do not. The SDRC looked at the model of the state-federal-industry coordinated response to pseudorabies virus during eradication to develop a program able to evolve in the response to emerging diseases.
The first phase is identifying the emerging disease challenge and, according to Dr. Patrick Webb, director of swine health programs at the National Pork Board, building tools to identify those challenges faster. If SHIC or any of the organizations identifies an emerging disease of significance, then the SDRC can be stood up to recommend next steps.
The SDRC’s core team is in the midst of training for a standardized approach for addressing emerging, non-regulatory diseases threatening the U.S. swine herd, per Dr. Webb. When notified, the SDRC will analyze information from SHIC or any organization engaged in the process. The SDRC has no regulatory authority. Effective response to an emerging disease will rely on pork producers and their veterinarians voluntarily following the recommendations of the SDRC, which may be temporary in nature until more information is gathered.
Dr. Webb calls the SRDC response plan a cookbook. It will have the industry steps, options, and scenarios for responding to emerging disease threats. The response will be developed based on the information available about the outbreak.
Based on evidence presented, Dr. Webb said the SRDC will have three possible types of response.
The SRDC cookbook provides a range of recommendations that covers everything from continuing to monitor the status of the disease to aggressive research, diagnostics, and biologic or voluntary or mandatory stop movements.
As the SDRC continues to develop, the core team will practice more scenarios, use past experience, and engage new technologies to achieve its mission.
Dr. Webb as well as Dr. Paul Sundberg of SHIC, Dr. Liz Wagstrom of NPPC, and Dr. Harry Snelson of AASV are staff for SRDC at this phase of its development. Questions about SRDC can be directed to Dr. Webb at 515-223-3441 or email@example.com.
When emerging swine disease arises, early communication about outbreaks is essential. Who do you call? Veterinarians and pork producers need to know who to contact and how to proceed in these events, beyond their diagnostic work and caring for the affected herd, so information can be used to protect the health of the US herd. A suggested communication strategy protects the confidentiality of the producer until permissions are given, provides the process to follow and outlines the resources available.
The Swine Health Information Center (SHIC) initiated the development of the process which provides for confidentiality of the producer or veterinarian making initial calls. Any actions because of those calls will maintain confidentiality to the level requested by the producer or veterinarian unless state or federal swine health regulations dictate otherwise.
As a disease is addressed on the farm, the veterinarian will examine the animals and, if needed, submit tissues to a veterinary diagnostic lab for investigation or confirmation. If a clear diagnosis is not determined, resources are available through SHIC’s Diagnostic Fee Support process for further investigation. Should these diagnostics point to a new or emerging pathogen, producers and/or their veterinarians can contact a veterinarian with the American Association of Swine Veterinarians, National Pork Board, National Pork Producers Council or SHIC. Together these experts will work with producers and their teams to coordinate response options.
This communications plan provides a structure for sharing information, informing industry stakeholders, engaging resources, and assuring the US swine herd is protected. For more information, contact SHIC Executive Director Dr. Paul Sundberg at (515) 598-4553 or firstname.lastname@example.org.
In cases of high or ongoing morbidity or mortality, where cause is either not identified or diagnosis is questionable, the Swine Health Information Center (SHIC) may be able to help pay for further diagnostic work.
Because there is risk of missing an emerging disease if a definitive diagnosis is not pursued diligently, SHIC recognized limitations on resources may be a barrier and developed this program to assist at the production level for the benefit of the national herd.
To qualify for fee assistance, the diagnostician of the case needs to initiate the process and the following requirements must be met:
When questions are more plentiful than resources for diagnostic work, SHIC can help! For more information, contact SHIC Executive Director Dr. Paul Sundberg at (515) 598-4553 or email@example.com.