Impact of a porcine epidemic diarrhea outbreak on swine productivity in Japan: a retrospective cohort study

YAMANE, Itsuro; YAMAZAKI, Hisanori; ISHIZEKI, Sayoko; WATANABE, Yugo; OKUMURA, Hanako; OKUBO, Mitsuharu; KURE, Katsumasa; HAYAKAWA, Yuiko; FURUKAWA, Makoto; OOI, Munetaka; MIZUKAMI, Yoshihiro; ITO, Mitsugu

This study demonstrates that the L-PED-positive herds had significantly reduced productivity, characterized by higher PRWM and POWM and lower PWL, during the PED epidemic. We observed similar result in the S-PED-positive herds, and the lack of significant differences between the S-PED-positive and other groups might be attributable to the small sample size (n=10) of this group. Among the PED-positive herds, the maximum PRWM was 45%, which was close to that of another study (21.7%) [8] , but lower than those reported in other studies, in which piglets under 2 weeks of age displayed much higher mortality (>90%) [7, 12] . This discrepancy might be attributable to differences in the ages of the suckling pigs targeted for investigation, the methods used to calculate suckling pig mortality in the different studies, virulence between different strains and farm managements between different countries.