Evaluating the Distribution of Porcine Epidemic Diarrhea Virus, Porcine Reproductive and Respiratory Syndrome Virus, and Seneca Valley Virus 1 Inoculated Feed after the Use of Physical or Chemical Mitigants to Flush a Feed Manufacturing Facility

Contaminated feed is a route of virus transmission between feed mills and swine farms.To reduce the risk of transmission, an understanding of the virus distribution and mitigation strategies are needed.The objective of this study was to evaluate the distribution of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and Seneca Valley virus 1 (SVV1) inoculated feed in the environment and feed of a feed mill before and after the use of chemical mitigants.A 50-lb batch of feed was run through a mixer and bucket elevator followed by a batch inoculated with PEDV, PRRSV, and SVV1.Following the virus-inoculated batch, a flush treatment of either 1) ground corn (GC); 2) GC + 1.5% liquid formaldehyde (LF; SalCURB LF Liquid, Kemin, Des Moines, IA); 3) GC + 1.5% LF + 25% abrasive material (SalCURB; Shell & Bone Builder, Iowa Limestone Company, Urbandale, IA); 4) double flush -GC + 25% abrasive material followed by GC +1.5% LF (Shell & Bone Builder; SalCURB); or 5) dry formaldehyde (SalCURB F2 Dry, Kemin, Des Moines, IA) was utilized, followed by 3 virus-free batches of complete feed.Feed and environmental samples were collected from each piece of equipment following every batch.Dust samples were collected after manufacturing from the inoculated, flush, and final batches from non-feed contact surfaces.Non-feed contact surfaces were considered