Researchers at Kansas State University found that antimicrobial properties of additives can protect pigs from the virus
By Jackie Clark
Researchers at Kansas State University are studying how feed additives may help mitigate the risk of African swine fever (ASF) transmission through feed.
“Historically, most of the feed additives have been looked at for their antimicrobial properties against bacteria, such as salmonella,” Dr. Megan Niederwerder, an assistant professor of diagnostic medicine and pathobiology at the university, told Farms.com.
Previously, the use of anti-microbial feed additives was mostly focused on food safety in the pork supply, however “after porcine epidemic diarrhea (PED) and this concept of feed being an avenue for swine diseases was introduced, there was a lot more research looking at ways to use these antimicrobial properties of feed additives on viruses and specifically swine viruses,” Niederwerder explained.
Researchers have investigated two main classes of feed additives, formaldehyde-based and medium-chain fatty acid-based, in their efficacy to protect against PED.
“We took those two additives because of that previous research showing efficacy against another swine virus, and then wanted to investigate if these were efficacious against ASF,” Niederwerder said. First, they determined that the additives were efficacious at reducing the ASF virus in in vitro studies.
Then, Niederwerder and her team used a protocol that simulates transoceanic transportation of feed ingredients. They tested nine different ingredients with additives included at two different time points. In one treatment, the additive was included at the beginning of the model, simulating the addition at the country of origin. The second treatment involved including the additives 28 days later at the simulated time point of arrival in the United States.
The team tested the feed ingredients for ASF at 30 days.
The two time points allowed the scientists to determine if “the feed additive need an extended exposure to the feed ingredient to be efficacious or is it something that happens fairly rapidly,” Niederwerder explained.
“We found that both when the feed additives were incorporated prior to simulated shipments and at the time point where they would be simulated to arrive in the U.S., both time points seemed like they were efficacious to reduce virus infectivity in most feed ingredients,” she said.
“Only two feed ingredients ended up maintaining a positive level of ASF,” she added. Both were from 28-day time point treatment “so there could be some time dependency where the feed additives may be more efficacious if they’re allowed exposure to the feed ingredients for a longer period of time.”
Niederwerder and her team plan to conduct more research to confirm that hypothesis, as well as dial in the “lowest effective inclusion rate for the food additive,” to minimize costs to producers.
These feed additives could help to mitigate the risk of ASF infecting the North American swine herd, and would be safe for both pigs and humans.
“The formaldehyde-based feed additive that we used in this study is already FDA approved,” Niederwerder said, and medium-chain fatty acids are already incorporated into pig diets.
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