Sow herd incidence and prevalence study

摘要

In the fall of 2011 we began the first effort to describe the incidence and prevalence of PRRS infections in a sample of300 sow farms, representing approximately 900,000 sows (estimated 15% of the US sow herd) across 12 states. Veterinarians working with these farms report weekly PRRS status using the AAS V classification system (Holtkamp et al., 2010) for each farm beginning July 2009.