Detecting Porcine epidemic diarrhea (PED)-specific antibodies post inoculation with B. cereus, A. fumigatus or the combination of B. cereus and A. fumigatus. In comparison with the control group, lower PED-specific IgG antibodies were detected in the B. cereus group, the A. fumigatus group and the co-infection group than those of the control group from day 7 (p < 0.01) to day 14 (p < 0.05). A significant difference was found between the B. cereus group and the A. fumigatus group on day 7 (p < 0.05), and no statistic difference was found among the B. cereus group, the A. fumigatus group and the co-infection group on day 14. The data were expressed as the mean ± SD (n = 9; n = 6). *: p < 0.05; **: p < 0.01.