Strong swine biosecurity works because no single barrier has to carry the whole load.
Viruses can enter through animals, transport, people, aerosols, equipment, biological materials, feed and other routes. Which pathway matters most depends on the virus, geography and production system.
That makes viral mitigation in swine systems a matter of reducing exposure across multiple controllable points. Feed is one of them.
The evidence is not the same for every virus.
For PEDV, the feed pathway is well demonstrated experimentally. Contaminated complete feed recovered from affected commercial sites successfully infected naïve pigs through natural feeding behavior, providing direct proof that feed can act as a transmission vehicle under the right conditions.
PRRSV now has an important field-linked example as well. In one 2,500-sow PRRSV-naïve herd, investigators traced the outbreak to feed from a single bin. PRRSV recovered from that feed closely matched the virus detected in affected sows, and material from the same bin later transmitted infection to naïve pigs under experimental conditions. One case does not establish feed as the dominant PRRSV pathway, but it strengthens the evidence that the route is biologically credible.
For ASFV, controlled research has shown that infection can occur through naturally consumed contaminated feed at sufficient viral dose. The virus can also remain infectious in some feed matrices during simulated transport, with soybean meal among the matrices supporting longer survival. These are controlled exposure and survival studies, not evidence that feed commonly drives field outbreaks.
That distinction matters when deciding how much weight to put on any one control point.
Ingredient sourcing and holding strategies reduce exposure before ingredients reach the mill. Holding can contribute to viral decay, but time, temperature, virus and matrix all matter. In complete swine feed stored for 58 days at approximately 24°C, no infectivity was detected for PEDV, PRRSV or SVA in the study bioassays, aside from a documented PRRSV biocontainment breach. That supports extended storage as one option under defined conditions, not a universal holding-time rule.
Thermal processing addresses virus present at the point of manufacture. With PEDV, conditioning and pelleting reduced viral RNA and eliminated infectivity across several tested time-temperature combinations. The researchers also highlighted the next challenge of protecting feed from recontamination after processing.
Feed-mitigation technologies address another gap.
Controlled PEDV studies have shown that chemical mitigation with medium-chain fatty acids and formaldehyde-based treatments can reduce viral detection and infectivity. In some studies, the treatments were applied before deliberate viral contamination, allowing researchers to assess whether protection persisted after application.
Feed-mill hygiene is part of that same challenge. PEDV challenge research has shown that viral material can move quickly through feed-manufacturing equipment and persist across subsequent batches, meaning sequencing alone may reduce contamination without fully clearing it.
Feed is not the only route by which viruses can enter a swine system, and no feed intervention can replace the broader biosecurity program already protecting the herd.
Its value is that feed is one pathway producers can actively manage. Ingredient sourcing, holding, thermal processing, mitigation technologies, mill hygiene and downstream handling each address a different point of risk. The strongest programs bring those controls together based on the virus, matrix, operating conditions and evidence available.
That is ultimately where viral mitigation in swine systems becomes practical: not by trying to eliminate every possible exposure route, but by reducing risk wherever control is possible and making each layer of biosecurity work harder for the system as a whole.
Want to take a closer look at how feed biosecurity fits within your viral-mitigation program? Contact an Anitox Clean Feed Expert to review the pathways and control points relevant to your operation.