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ASF And Viral Threats: Understanding Feed Biosecurity In Swine Production
Outbreaks of African Swine Fever (ASF) and other viral pathogens have underscored the importance of comprehensive biosecurity measures that extend from ingredient sourcing to feed delivery.
Feed as a vector for viral transmission
The understanding that feed can transmit viral diseases represents a paradigm shift in swine health management.
"The global nature of feed trade combined with the environmental stability of major swine viruses creates a perfect storm for transboundary disease transmission," explains Dr Francisco Domingues, Anitox global technical director of Swine Markets. "What we've learned from recent research is that feed biosecurity can no longer be an afterthought in swine production systems."
A growing body of scientific literature confirms that feed ingredients can harbour and transmit economically devastating swine viruses. Multiple experimental studies have demonstrated that porcine epidemic diarrhea virus (PEDv), porcine reproductive and respiratory syndrome virus (PRRSv) and African Swine Fever virus (ASFv) can survive in feed components for extended periods under conditions simulating commercial transport.
In landmark transport simulation studies, researchers documented viral viability in feed ingredients over remarkable durations:
"These findings should fundamentally change how we think about feed security," notes Dr Domingues. "We're not just talking about theoretical risk – we have concrete evidence of viral persistence in common feed ingredients traveling across continents."
The research goes beyond merely detecting viral presence in feed, having confirmed that contaminated feed can establish infection in naïve animals through natural feeding behavior. A minimum infectious dose of ASFv has been quantified as 10⁴ TCID₅₀, however, the median infectious dose in feed was 10⁶·⁸ TCID₅₀. While these doses are higher than those required in liquid matrices (minimum 10² TCID₅₀), they demonstrate that feed can serve as a viable route to initiate infection.
Impact of ASF and other viruses on global swine production
"The introduction of African Swine Fever virus has fundamentally altered the global swine industry landscape, with impacts that will be felt for years to come," notes Dr Domingues. "What makes ASF particularly concerning is its combination of high mortality and absence of effective vaccines or treatments."
The scale of this impact is particularly pronounced in Asia, home to over 50% of the world's pig population. Following ASF introduction to China in 2018 and subsequent spread throughout Southeast Asia, the region experienced:
These impacts extend far beyond infected regions. As documented, the cascading effects of major outbreaks include disruptions to global meat supplies, shifts in international trade patterns and economic losses that reverberate throughout agricultural supply chains and rural communities.
While ASF has dominated recent headlines, swine producers face a complex viral landscape that includes other significant pathogens:
"The concurrent circulation of multiple viral threats creates compound challenges for producers," explains Dr Domingues. "Control strategies must account for the unique characteristics of each pathogen while addressing common transmission pathways."
The absence of an effective vaccine or treatment distinguishes ASF from many other swine diseases, placing extraordinary emphasis on prevention. This gap in the disease control toolkit makes understanding transmission pathways –including the role of feed – critical to developing effective biosecurity strategies.
Feed component risk profiles and mitigation strategies
"Understanding which ingredients pose the highest risk allows producers to implement targeted mitigation strategies," states Dr. Domingues. "Not all feed ingredients carry equal risk. For instance, studies have shown that soy products demonstrate high viral survival, which helps to inform both sourcing decisions and treatment protocols."
Dr Francisco Domingues, Anitox global technical director of Swine Markets Feed sanitisers significantly reduced detectable viral RNA (PEDv, PRRSv, and SVV1) in soybean meal – an ingredient specifically highlighted in the research as a concern. Testing revealed effective viral reduction at both low (2 kg/MT) and high (3 kg/MT) inclusion levels, providing options for treating this high-risk ingredient. When treating high-risk ingredients like soybean meal, the research showed a significant interaction between application timing and treatment effectiveness. Post-contamination application (mitigation approach) resulted in substantially lower viral RNA levels compared to preventative treatment, suggesting that rapid response to known contamination in high-risk ingredients is particularly effective.
"Feed sanitisers are an important option for the industry, with some producers finding them to be non-negotiable in their biosecurity toolbox. We are not just trying to mitigate or reduce the viral DNA during the application or inside the feed mill. We need tools that can guarantee protection against recontamination until the point of consumption," emphasises Dr Domingues.
Comprehensive feed mill biosecurity
As global swine production continues to face threats from viral pathogens like ASF, PED, and PRRS, feed biosecurity has become an essential component of comprehensive disease prevention strategies. The recognition that feed can serve as a vector for viral transmission has fundamentally changed how the industry approaches biosecurity.
"Publications documenting the aftermath of previous outbreaks have shown how difficult it is to clean up a feed mill after it has become contaminated with viruses, such as PEDv or even ASF. It can take months to get that feed mill clean again," notes Dr Domingues. "The evidence is clear that feed represents a viable transmission route for major swine pathogens. As our understanding grows, so too must our approach to feed biosecurity. The future of sustainable swine production depends on recognizing and addressing this critical control point."
Producers looking to further strengthen their operations' biosecurity via feed sanitation should contact their Anitox Clean Feed Expert.
References available on request.
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Anitox is dedicated to feed microbial quality and efficiency, supporting producers by protecting feed value through an expert understanding of feed-source pathogens and the importance of feed form. Anitox partners with the world's food producers to develop and deliver innovative programs to efficiently produce safer food.
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Anitox is dedicated to feed microbial quality and efficiency, supporting producers by protecting feed value through an expert understanding of feed-source pathogens and the importance of feed form. Anitox partners with the world's food producers to develop and deliver innovative programs to efficiently produce safer food.
'Piglet Smoothie' Fed To Sows To Prevent Disease; Activists Outraged
Enlarge this image A screen grab from an undercover video released by the Humane Society of the U.S. Shows a pig in a gestation crate at Iron Maiden Farms in Owensboro, Ky. Courtesy of The Humane Society of The United States hide caption
toggle caption Courtesy of The Humane Society of The United StatesA screen grab from an undercover video released by the Humane Society of the U.S. Shows a pig in a gestation crate at Iron Maiden Farms in Owensboro, Ky.
Courtesy of The Humane Society of The United StatesAnimal welfare groups go to great lengths to show us how "the sausage" is made inside the factory-style farms that produce most of our meat. For the past few years, they've armed activists with video cameras and sent them undercover to document alleged abuses or risky practices.
On Thursday, the Humane Society of the U.S. Released its latest video — a look at how one hog farm in Kentucky is dealing with porcine epidemic diarrhea virus, or PEDV. The fast-spreading virus has killed more than 2 million piglets in 25 states in the U.S. Since April 2013.
Sponsor MessageLet's just say it isn't pretty. (The video is available on the Humane Society's website, but we should warn you that it's very, very graphic.)
In this video, we learn what happens to the piglets at Iron Maiden Hog Farm in Owensboro, Ky., that succumbed to the virus: The animals' intestines are ground up and fed, as a "smoothie" — as HSUS dubs it — back to the sows, which could be their own mothers. (The exact size of the farm is unknown, but the barn shown in the video houses about 2,400 sows.)
The Salt Pig Virus Continues To Spread, Raising Fears Of Pricier Bacon "It's beyond disturbing seeing piglets being prepared for this process," the unidentified narrator, an HSUS activist, tells viewers. "It seems obvious that confining pigs in such an environment that causes open sores, extreme stress and filthy living conditions would only encourage the spread of disease."
Before we see the pile of dead piglets, we're shown how the sows at Iron Maiden are confined to narrow stalls that severely limit the animals' movement. No surprise here — these gestation crates are common in the industry, and animal welfare experts have long called on farmers to do away with them. (Many big producers are now moving away from the crates, as we've reported.)
But the HSUS says the practice of feeding dead pigs to live pigs is illegal in the state of Kentucky and may violate federal law, too. The Swine Health Protection Act prohibits feeding untreated garbage, which could be animal material, to pigs, unless it's "household waste."
"Pig factory farms are not 'households,' and killing piglets is not a 'household operation,' " HSUS Vice President Paul Shapiro tells The Salt.
But hog farmers and veterinarians say that while feeding the guts (or stool) of dead piglets back to sows may sound icky, it's the only option they've got to keep the dreaded PEDV from decimating herds and the whole of the U.S. Hog supply.
In a statement posted on Facebook, the Kentucky Livestock Coalition, a group representing farm groups in the state, called it a "widely-accepted and veterinary-recommended management practice."
Tom Burkgren, executive director of the American Association of Swine Veterinarians, says that there are no vaccines or drugs to give to sows so their piglets won't get the lethal virus. That means the only tool farmers have is "controlled exposure," or feeding the remains of sick piglets to sows.
What's more, he says, "controlled exposure" has been used for decades to protect animals against rare diseases. While PEDV has been in the U.S. For only one year, the technique appears to be working against it, he says.
"When I'm faced with the choice of seeing and carrying hundreds of dead baby pigs out of a barn or overcoming the 'ick factor,' I'm going to get over that 'ick factor,' because my goal is to save lives," Burkgren says. (Burkgren adds that mother pigs sometimes cannibalize their babies like this on their own — he's seen it on farms where pigs are confined and also ones where they're allowed to pasture.)
Sponsor MessageBut the HSUS points out that there's a higher risk of infection in large industrial hog operations like Iron Maiden, compared with smaller farms that raise their pigs outdoors. And Michael Blackwell, senior director of veterinary policy for HSUS, says farmers do not necessarily have to resort to feeding pigs to pigs to prevent the spread of PEDV.
"Keeping animals in a distress-free environment would help their immune systems. PEDV is a sentinel of the system not being in the best interest of the health of the animals," Blackwell told reporters in a press conference. "We know we have limitations in the system in terms of inadequate space and nutrition."
As for HSUS's allegations of general abuse of the sows at Iron Maiden, Brent Burchett, a spokesman for the Kentucky Livestock Coalition, told The Salt in an email: "I have personally toured this farm. ... After watching the video, I believe it does not reflect the values of the producer in question."
Why A Deadly Pig Disease Has The U.S. Scrambling For A Solution
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