The incidence of porcine circovirus-associated disease (PCVAD) can be reduced by selecting for 65-day weight along with porcine circovirus (PCV2) viremia and antibody titers, conclude Jared S. Bates, University of Nebraska, and colleagues in their report ‘Selection for Immune Responses to Porcine Circovirus (PCV2) to Decrease Incidence of Porcine Circovirus Associated Disease’
The report found that immune responses to PCV2 are heritable. However, it would take considerable time for such a strategy to significantly reduce the incidence of PCVAD in commercial herds.
Several generations of selection will be required to greatly reduce the incidence and this selection must be practiced in nucleus herds and then transmitted through the breeding pyramid to commercial populations.
Furthermore, response to selection for PCVAD scores, viremia, and antibody levels will occur only if all pigs in nucleus populations are exposed to PCV2 so that variation reflects genetic variation in the traits.
Genomic selection for resistance to PCV2 and decreased incidence of PCVAD may be the most effective long-term selection strategy.