PEDV continues to be spread between herds in the US. Livestock transport to harvest plants has been identified as a likely route of PEDV movement between herds. In this study we assessed which physical factors at the packing plant were likely to contribute to the contamination of livestock trailers with PEDV at the time of unloading. We did this by building a model for the unloading process that could be manipulated to look at factors that occur over time at harvest plants like temperature changes and the amount of manure present on the unloading dock. What we found was that within reasonable limits that happen under commercial conditions temperature on the dock or on the trailer did not influence the amount or frequency of PEDV found 1 hour after the simulated unloading event. In addition, increasing UV light on the dock did not lower the contamination rate of the model trailer. We did find that removing manure was effective in lowering but not eliminating the frequency of PEDV found on model trailer 1 hour after contact. It appears that lowering the amount of manure on the unloading dock is a way to reduce but eliminate PEDV spread between farms that occurs at harvest plants but is not a substitute for effective cleaning and disinfection of livestock trailers. For more information contact: Dr. Jim Lowe, [email protected].