The first objective has to be to work with a stable farm. To do so, own production gilts have to become positive to the disease but they have to enter the herd (as breeding animals) PCR negative.
I would recommend to house own replacement isolated from the rest of the herd and in a continuous flow until the farm PRRS virus circulates and the gilts become PRRS positive. Thereafter they have to be vaccinated and isolated to give them the chance to stop shedding.
Once they stop shedding (PCR negative status) they can come into the herd. Obviously PRRS acclimatization has to be combined with other vaccines and production management.
To have a stable herd it would be also recommended to establish a sow’s vaccination protocol (3-4 times a year) using a Modified Live vaccine, and being sure semen comes from negative PRRS boars.
Marcovetgrup S.L. – Spain