Fig. 1

Immunoreactivities of synthetic peptides were carried out with those sera from unvaccinated naturally PCV2-infected pigs in comparison with sera from PCV2-negative pigs. a In the unvaccinated naturally PCV2-infected pig farm, 22 newborn piglets of TBP, were delivered from 11 sows during 4 seasons of 1 year. Blood samples from each pig were collected 4 times at aged 1 day (after colostrum uptake), 1 month, 3 months and 6 months. b 20 PCV2-negative sera (4 each from 1-week, 1-month, 2-month, 3-month, and 6-month old pigs) were collected from the PCV2-negative herd in the primary specific pathogen free (SPF) pig facility. Synthetic peptides were used in indirect ELISA to measure immunoreactivitiy with these pig sera (each serum dilution 1:100). All samples were assayed twice. Error bars indicate SD from the mean. Significant p values are indicated as *p < 0.05. Statistical significance was calculated using paired Student’s t-test