I will explain it like this. My mother's family farmed and had hogs. They went to confinement in the 60's. Well mom married a farmer that milked and that's how I came about. Although we have beef cattle and farm now, no dairy herd. Thank God. Anyway, PRRS and other illnesses would decimate a pig farm. My grandpas employees were not allowed to be at any place there was swine nor could they have them. It was sanitize into the buildings. Every other week a semi came in for a load of butcher pigs. Truck and trailer had to be sanitized and washed prior to entering the farm. Pigs were loaded from an outside pin and not from the finishing house. Once a pig went on the trailer, it could not come off. If at any time a pig got off the trailer, it was shot where it stood. Period not up for discussion. Sale barns were off limits. Etc. you get the drift I'm sure.