Fig. 1.

Longitudinal analysis of IgG response to PToV in pigs from three Spanish herds. Serum samples from 120 piglets and 30 sows were collected from three farms. Samples collected at weeks 1, 3, 7, 11 and 15 of piglet age and samples from sows collected at 1 week post-farrowing were analyzed for the presence of IgG to PToV-N protein by ELISA. (A) Percentages of seropositive (black bars) and seronegative (grey bars) animals over the study period. (B) Mean IgG ELISA values of sows and piglets at each sampling time are represented by grey and black squares, respectively. IgG ELISA cut-off value is indicated (- - -).