ASF Contamination in Feed: What the Evidence Says and What To Do About It

When African swine fever (ASF) shows up in a region, most producers immediately think about pigs, people, vehicles, and wild boar. However, if you manage swine health long enough, you learn a hard truth: most catastrophic events are not caused by a single failure. They happen when multiple small, “reasonable” gaps line up. That is exactly why ASF contamination in feed remains on the industry’s radar—not because feed is always the most likely route, but because it is a repeatable, scalable exposure pathway that can be engineered down with disciplined controls. 

Survival: can ASFV persist in feed and ingredients long enough to matter? 

Evidence indicates it can. A transboundary shipping model study demonstrated survival of ASFV (among other livestock viruses) in feed ingredients exposed to time/temperature/humidity patterns meant to replicate long-distance shipment, reinforcing that certain matrices can protect virus through the exact supply-chain window many ingredients experience. In practical terms, this means that if a contaminated ingredient enters commerce, the passage of time alone may not reliably eliminate risk before it reaches a mill or farm. 

This is strengthened by an Emerging Infectious Diseases analysis estimating ASFV half-life across nine ingredients under 30-day shipment conditions, with half-lives on the order of days to weeks. The operational implication is direct: ingredient sourcing and receiving are true control points for ASF contamination in feed, particularly for globally sourced, high-risk matrices, because viable virus can persist long enough to move with the ingredient. 

Dose: can pigs become infected by eating or drinking contaminated material? 

Yes—oral exposure is experimentally supported. In Emerging Infectious Diseases, researchers quantified ASFV infectious dose under natural drinking and feeding behaviors, demonstrating that exposure via liquid and feed can cause infection and providing estimated minimum/median infectious doses. For producers, this matters because the key variable becomes exposure: even if contamination levels are low, repeated intake across days and across many pigs can convert a “small” hazard into a meaningful outbreak probability. Put simply, ASF contamination in feed is not just theoretical; the route is biologically viable at realistic consumption behaviors. 

Mitigation: can interventions reduce infectivity if contamination occurs? 

Peer-reviewed work supports certain mitigants as risk-reduction tools. A Transboundary and Emerging Diseases study evaluated an MCFA-based additive and a formaldehyde-based additive in feed/ingredients under shipment-model conditions, reporting dose-dependent reductions in ASFV infectivity. The practical implication is that mitigation can serve as a redundancy layer—a backstop for inevitable imperfections in sourcing and handling—particularly when risk is elevated (new ingredient origins, uncertain biosecurity, regional ASF pressure). 

Mechanistically, additional peer-reviewed literature discusses MCFA and related compounds as candidates to inhibit ASFV infectivity in liquid and feed matrices. Importantly, this should be interpreted as “risk reduction,” not “permission to relax prevention,” because no mitigation strategy eliminates the need to keep contamination out of the system in the first place. 

A practical control plan for ASF contamination in feed 

Peer-reviewed syntheses emphasize that the best outcomes come from layered controls: source smart, reduce opportunities for contamination and recontamination, and deploy validated interventions where justified. In practice, that translates to (1) ingredient risk ranking and supplier verification anchored in survivability data, because viable virus can persist through transport windows; (2) feed mill biosecurity and hygiene to prevent recontamination after processing, because “clean in” can become “dirty out” through traffic flow, equipment, pests, or sequencing; (3) holding-time or storage strategies operationalized as an additional lever when feasible, because time can reduce risk but may not be sufficient on its own depending on matrix; and (4) targeted use of mitigants aligned to your risk profile, because evidence supports infectivity reduction and redundancy is what prevents single-point failures from becoming outbreaks. 

The modern evidence base supports a clear conclusion: ASF contamination in feed is a manageable, engineerable risk. Survival is documented under shipping-like conditions, oral infectivity is demonstrated under natural consumption behaviors, and mitigation options exist—so the farms and mills that perform best treat feed as a formal biosecurity domain with measurable controls, not an afterthought.