Fig. 2

Serum IgG antibody and nasal sIgA antibody titres detection of of all pigs from both Bama mininature pigs and conventional pigs. Serum and nasal swabs from all pigs were collected at 0 dpi and 28 dpi. D0: 0 dpi; D28: 28 dpi. a Serum IgG titres of M. hyopneumoniae from all pigs were tested by a commercialized ELISA kit. S/P value = (sample OD₆₅₀ - negative control OD₆₅₀)/(positive control OD₆₅₀ - negative control OD₆₅₀). S/P values higher than the cutoff value of 0.4 were considered positive. *, P < 0.05, indicates serum IgG S/P values between the infected and control groups of conventional pigs were significantly different. **, P < 0.01, indicates serum IgG S/P values at 0 dpi and 28 dpi were extremely significantly different. b sIgA titres of M. hyopneumoniae collected from nasal swabs of pigs measured using a lab-prepared ELISA kit. S/P value = (sample OD₄₅₀ - negative control OD₄₅₀)/(positive control OD₄₅₀ - negative control OD₄₅₀). *, P < 0.05, indicates nasal swab sIgA S/P values between the infected and control groups of both Bama mininature and conventional pigs were significantly different. **, P < 0.01, indicates nasal swab sIgA S/P values at 0 dpi and 28 dpi of infected pigs in both Bama mininature and conventional pigs were extremely significantly different