As African swine fever virus (ASF) circulates throughout China and other Asian countries, researchers are continuing to investigate the virus’ ability to survive in feed.
“Because there is no vaccine and no treatment [for ASF], the focus of our research has really been to understand the risk, and then ways that we can put in mitigation strategies to reduce the risk,” said Megan Niederwerder of Kansas State University Veterinary Diagnostics on AgDay TV.
The ASF virus’ half-life in feed is longer than researchers originally thought, and Kansas State researchers say that can be a problem with feed coming from other countries.
“Since the introduction of PEDV [porcine epidemic diarrhea virus] and the recognition of feed as a potential risk, our goal has been to understand what's the risk of feed for other foreign animal diseases. And the biggest one at this time point for pigs and animal health globally is African swine fever,” Niederwerder explained.
One of the most interesting things researchers discovered was that all of the half lives in feed and feed ingredients were longer than the half-life that they calculated in media, the material used in tissue culture and in the lab to support the virus, Niederwerder said.
“What we ultimately found was that these feed and feed ingredients have the composition, the protein content, the moisture content that increases stability of the virus when compared to that media,” she said.
What’s the best way to mitigate this risk?
Put multiple steps in place, she advised. Source feed ingredients locally and if that’s not possible, look at low-risk ingredients for importing or low-risk countries of origin for importing. Use procedures to store or hold feeds for advised periods of time after they arrive and before feeding to pigs.
The other mitigation strategy that they are currently researching is looking at temperatures that can increase the speed at which the virus decays in feed ingredients, she said. They are also exploring several anti-viral chemical mitigants as potential feed additives to reduce the risk of the virus being transmitted.
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