Project Title: Evaluation of sampling and testing strategies for monitoring of PRRS virus infection in boar studs

Institution: University of Minnesota

Outcome/Results: Protocols based on using PCR to test serum detected PRRSV introduction earlier than other protocols tested using serum or semen.

Summary: Monitoring of boar studs for PRRS is critical to minimize the risk of transmission to sows via contaminated semen. However, current protocols for monitoring PRRSV in boar studs are diverse, sometimes very costly, and their effectiveness has not been examined quantitatively. The objective of this study was to compare various monitoring protocols in their ability to detect a PRRSV introduction in a negative boar stud, using a simulation modeling approach. Our findings indicated that protocols based on PCR on serum detected the PRRSV introduction earlier than protocols using PCR on semen, and use of PCR on semen detected the PRRS introduction earlier than using ELISA on serum. A strong effect of sample size but not of sampling frequency was observed. This study support field observations suggesting that an intensive monitoring protocol needs to be in place in a boar stud to quickly detect a PRRSV introduction.