PRRS Eradication by Herd Closure

The first and most important thing is to evaluate whether we can keep the system negative during and after the eradication program. A reasonable understanding on how the virus entered the unit is the starting point. Although this may sound basic, we tend to forget about it. We have documented various PRRS breakdowns in negative systems. In these systems, after pigs and semen are excluded, transport, people, equipment movement and local pig density were identified as the most likely factors responsible for the infection.