The entrance of gilts is one of the main causes of destabilisation of PRRS in swine farms, and a source of the entrance of new PRRS virus strains into breeding herds. In order to prevent this from happening, and either the new breeding sows or the herd they are being introduced into becoming infected, a series of protocols must be put in place. Management of gilt entrance into a farm is very, very important.

Firstly, the animals must be quarantined. By this process the incoming animals can be observed and tested in isolation. This will allow the producer to ascertain whether the incoming gilts have been exposed to PRRS before, either the homologous strain (already found on the farm), or heterologous (not already existing in the farm).

During quarantine the gilts are tested for either the presence of, or past exposure to, the PRRS virus.

These tests are done with both PCR (polymerase chain reaction) procedures, and serological tests.

These will tell the producer if the gilt has been exposed to PRRS, and which strains if they have. This is very important, because if a gilt has a strain of PRRS which is not homologous to the farm, that gilt cannot be introduced into the breeding herd.

The gilt can join the breeding herd after this process, but must first be immunised. This will happen either through vaccination or virus exposure, but before joining the herd on a farm that has viremic stock. This process is called 'acclimitisation', and is key to avoiding the destabilisation of the breeding herds.

From beginning to end, this process should take roughly 8 – 12 weeks.

With this new tool HIPRA is consolidating its commitment to PRRS control and reinforcing its positioning as reference in prevention for Animal Health.

To view the Hipra video and more on PRRS, click here.