Work underway to halt the spread of deadly swine viruses in feed
The Foundation for Food and Agriculture Research (FFAR) announced that it was supporting Pipestone Applied Research’s study with a Rapid Outcomes from Agricultural Research (ROAR) grant earlier this month.
The research team is testing 10 commercially available disease mitigants, or feed additives, to assess whether they can deactivate Porcine Reproductive and Respiratory Syndrome (PRRS), Porcine Epidemic Diarrhea (PED) virus and Seneca Valley A (SVA), a relative of foot and mouth disease. The team said the research may be relevant to preventing the introduction other viruses, such as African Swine Fever Virus (ASFV), to a herd.
The mitigants are added to feed containing the viruses and then fed to pigs in a commercial setting, to replicate on-farm conditions.
The feed and disease challenge trials initially started in November 2018, said Scott Dee, research director at Pipestone Applied Research, and lead researcher on the project. Initial funded came from industry and the Swine Health Information Center (SHIC) and FFAR provided $150,000 in matching funds.
The project team wants to see if the feed additives could reduce or eliminate the presence of the virus or keep the animal consuming that feed from becoming sick, he said.
“These additives are not made for that specifically – they’re made more for pig health, and growth and nutritional value, but some of them appear to have some ability to reduce viral survival in feed or reduce viral quantity in feed,” he told FeedNavigator.
“The goal is, by the end of the year, to have close to 15 or so evaluated in a model we developed,” he added.
Results are also set to be shared with researchers at Kansas State University (KSU) and applied to feeding trials related to ASF, Dee said. “I’m very positive about what we’ve seen so far, and I’m looking forward to testing more products this year; some of these are going to have a very good chance of reducing ASF in feed."
There are wider implications from this research effort. “This is directly applicable to other animals, even potentially pet food,” he added.
Understanding virus survival
Interest in address the spread of viruses through animal feed started with an outbreak of the Porcine Epidemic Diarrhea Virus (PEDV), Dee said. The disease killed about 10% of the US swine herd in 2014.
“We started thinking about how viruses could move in feed and we did several studies."
That project followed 11 diseases through a modeled importing process to see which were able to survive transport in feed or feed ingredients.
Mitigants, diseases in feed
The current research project exploring feed additives' ability to deactivate viruses is examining several that are commercially available and some that are not on the market, said Dee.
PRRS, PED, and SVA viruses are a concern for both domestic and international producers, he said.
Research related to ASF, a virus that has devastated the Chinese pork industry and has been detected in Europe. requires specific laboratory conditions, so trials linked to the feed additives and that virus is being done in a biocontainment facility at Kansas State University, Dee said.
"If a mitigant is effective against Seneca Virus A – one could hypothesize that it would also be effective against ASF,” he added.
Pipestone swine research facility has the ability to test five separate mitigates at one time, using up to 100 pigs per trial, he said. An ice block containing the diseases is added to the feed and then given to the pigs.
“We let the pigs naturally consume the feed like they would if they were on an actual farm,” he said. “It’s a hot spot model or a point in time contamination model."
Pigs are then observed to see if they contract the disease and show symptoms of being ill, he said. Growth measures are taken as part of the effort to understand what role a mitigant might be playing.
“We’re looking at what the mitigants can do to the virus and how they can help protect the pigs versus feed that doesn’t get treated,” he added.
Initial findings from the first phase of trials have been positive, Dee said. Adding, “It’s been really interesting – the pigs that consumed feed that was not treated, that did not have a mitigant, [have become infected] and [present with] clinical disease.”
“In the [group of pigs receiving] mitigants, we’re seeing the opposite – the virus might be there, but it’s in really low quantities now, and the pigs are not getting sick; they’re growing really well compared to the pigs that get the virus without the mitigates,” he said. “It looks like the mitigants are basically performing equal to one another and they’re all better than the non-mitigated group.”
The project has examined a range of product types including acids, fatty acids and several formaldehyde-based products, he said.
The next piece of the project will be an additional series of trials and results are set to be shared with producers and the industry, Dee said. Adding, “It doesn’t do the industry any good if only one company has it, everybody needs this information.”
The official end date for the trials is later this year, but there may be interest in working past that point, he said. “This is a pretty hot topic, and it’s going to roll for a while.”
