Fig. 3From: Coinfection with Haemophilus parasuis serovar 4 increases the virulence of porcine circovirus type 2 in pigletsDetection of anti-PCV2 antibodies. Serum samples were collected on days 0, 1, 3, 5, 7, 14, 21 and 28, respectively, and anti-PCV2 antibodies determined by ELISA. The horizontal line represents cut off value for assayBack to article page