Brazilian pig population is made up of several naturalized breeds; among them the Piau breed is known for its rusticity and large fat stores. The naturalized breeds, in comparison with commercial ones, may have an increased resistance to diseases circulating in their territory. Thus, this study aimed to verify if there are differences between the serologic profile against Porcine circovirus 2 (PCV2) of Piau pigs and that of a commercial breed from a farm naturally infected by PCV2. The serum viral load was measured by qPCR, and levels of anti-PCV2 antibodies were measured by ELISA. The results showed that the serum viral load was similar across all animals. However, Piau piglets showed higher levels of antibodies compared to commercial piglets (P= 0.05), while sows of the commercial breed showed higher levels than the Piau breed (P< 0.01). There was not a statistical difference between pigs of different production stages in the seroprevalence of PCV2 or the blood viral load. This work demonstrates that, with regard to a natural PCV2 infection, the Piau breed has a different humoral immune response compared to the response developed by the commercial pigs. The results support the importance of conservation of native breeds.
serum viral load; serology; Piau