Swine producers invest heavily in biosecurity, controlling everything from animal movements and transportation to personnel and farm access. Yet one potential route of viral exposure can receive considerably less attention: the feed delivered to those same farms.
Over the past decade, research into porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV) and African swine fever virus (ASFV) has challenged longstanding assumptions about feed safety. The evidence varies by virus, but it is increasingly difficult to justify leaving feed out of the biosecurity conversation.
Listen to the episode: Risk-Based Feed Biosecurity Today.
For producers focused on herd biosecurity and sustainable performance, the challenge is deciding where additional protection makes sense, which interventions are supported by evidence and how to prioritize investment without adding unnecessary cost or complexity.
In an episode of the Frankly Speaking podcast, Dr. Francisco Domingues, Anitox Global Head of Swine Nutrition and Health, discusses five priorities for managing feed-related viral risk while balancing herd protection, operational realities and cost.
Feed is one of several potential pathways for viral exposure in swine production. Its relative importance depends on the virus, ingredient sourcing, manufacturing conditions and production system. Effective feed biosecurity combines risk assessment, validated interventions and coordination between nutrition, veterinary and operations teams rather than relying on a single control measure.
Historically, feed received less attention in viral biosecurity planning than animal movements, transportation and personnel. That began to change following the emergence of PEDV in North America in 2013.
Subsequent research demonstrated that contaminated complete feed collected from affected commercial farms could infect susceptible pigs through natural feeding behavior, establishing that feed can serve as a transmission vehicle under certain conditions.
Additional studies found that several swine viruses could remain infectious in selected feed ingredients under simulated transboundary shipping conditions, raising further questions about ingredient sourcing and movement.
These findings do not establish that feed is the primary transmission pathway for every virus or production system. They do, however, support treating feed as a credible exposure route that warrants consideration alongside established biosecurity controls.
Feed processing can contribute to microbial and viral risk reduction, but its effectiveness depends on operating conditions.
Temperature, retention time, feed characteristics and equipment configuration all influence the outcome of thermal treatment. These variables become particularly important when comparing commercial feed-mill conditions with controlled experimental studies.
Research has demonstrated that PEDV inactivation in swine feed depends on both temperature and exposure time. However, those findings cannot automatically be applied to other viruses or processing systems.
As Dr. Domingues emphasized during the podcast, feed mills vary considerably in their conditioning equipment and operating parameters. Meeting a particular processing temperature does not, by itself, demonstrate effective viral inactivation.
Thermal treatment also provides no inherent protection against subsequent contamination. Finished feed may encounter additional exposure opportunities during cooling, conveying, storage and transportation.
Chemical feed interventions offer another potential means of reducing viral risk, particularly where heat treatment is unavailable, insufficient or followed by opportunities for recontamination.
However, not all interventions deliver equivalent results.
Their effectiveness can vary according to the virus, chemical formulation, inclusion rate, feed matrix and treatment conditions. Controlled studies have demonstrated reductions in ASFV infectivity using certain feed additives, while PEDV mitigation research has shown differences in effectiveness between treatments.
These findings demonstrate why efficacy cannot be assumed across products or pathogens.
Dr. Domingues also highlighted the importance of residual activity. An intervention that reduces viral infectivity during initial treatment does not necessarily provide protection against contamination occurring later in the feed supply chain.
For nutritionists and veterinarians evaluating treatment options, the critical questions concern whether the product has been tested against the relevant virus, whether the proposed inclusion rate is supported by evidence and whether efficacy has been demonstrated under conditions representative of commercial use.
Not every farm or production stage faces the same disease pressure or potential economic consequences. That makes risk-based feed biosecurity more useful than applying identical interventions across an entire production system.
As Dr. Domingues explained on Frankly Speaking, feed biosecurity decisions should reflect the disease challenges facing individual operations. For systems managing PEDV or PRRSV, breeding herds, nucleus farms and genetic multiplication facilities may warrant particular attention because disruptions at these sites can affect reproductive performance, piglet supply and downstream production.
ASFV presents a different risk profile, particularly in regions where the virus is circulating or where the consequences of introduction could include substantial animal losses and movement restrictions.
Experimental research has established that pigs can become infected with ASFV through consumption of contaminated plant-based feed, although the infectious dose differed from that observed through liquid exposure.
The objective is not necessarily to apply the same intervention everywhere, but to identify where additional protection offers the greatest potential value.
The economics of feed biosecurity extend well beyond the cost of treatment per ton.
Viral outbreaks can affect reproductive performance, mortality, growth, animal movement and production continuity. In severe cases, the financial consequences can extend across multiple stages of an integrated production system.
These costs make prevention worth evaluating before an outbreak occurs. However, the potential cost of disease alone does not establish the financial value of a particular intervention.
For a practical assessment, nutritionists and veterinarians should consider four questions:
Answering these questions together helps distinguish necessary protection from additional expense that may offer limited value.
This is where collaboration between veterinary, nutrition and operations teams becomes particularly important. Disease surveillance, sourcing decisions, feed manufacturing capabilities and intervention costs all contribute to determining which preventive measures are justified.
Feed is neither the only potential pathway for viral introduction nor a risk that can be managed independently of the broader production system.
Effective prevention depends on coordinated decisions around animal health, ingredient sourcing, feed manufacturing, logistics and farm biosecurity.
For swine producers pursuing herd biosecurity and sustainable performance, the opportunity is to move beyond treating feed as a passive input and recognize it as another controllable part of disease prevention.
That does not mean every operation needs the same intervention. It means using the available evidence to identify meaningful risks, prioritize vulnerable production stages and invest in controls that can deliver practical value.
The first step is recognizing feed as a potential route of viral exposure. The next is identifying which preventive measures make sense for your operation.
Hear more on the Frankly Speaking podcast, where Dr. Francisco Domingues explores the latest evidence on feed-associated viral risk, the limitations of conventional processing and practical approaches to strengthening swine feed biosecurity.
Listen to the episode: Risk-Based Feed Biosecurity Today.