Assessment of the cost effectiveness of compulsory testing of introduced animals and bulk tank milk testing for bovine viral diarrhea in Japan

ISODA, Norikazu; ASANO, Akihiro; ICHIJO, Michiru; OHNO, Hiroshi; SATO, Kazuhiko; OKAMOTO, Hirokazu; NAKAO, Shigeru; KATO, Hajime; SAITO, Kazuma; ITO, Naoki; USUI, Akira; TAKAYAMA, Hiroaki; SAKODA, Yoshihiro

A stochastic scenario tree model comprising nodes representing cattle categorization, immunity following vaccination, virus infection, and monitoring, which had been developed in a previous study, was used here with minor modifications to estimate the number of detected and missed BVDV-infected cattle [19] . Briefly, we presumed that we need to monitor the BVD risk in a target area with cattle movement from outside of the target area and set a number of targeting cattle in this study as a combination of 8,000 inherent cattle in the target area and 2,000 introduced cattle to the target area from outside (introduction ratio; 20%), doi: 10.1292/jvms. and both the components of this combination were divided into five age groups based on the immunity status against BVDV, probabilities of detection by clinical manifestation, and availability for lactation. The rates of age distribution in this study were the same as those in the previous study. The default probabilities of cattle being persistently or transiently infected as well as those of possessing sufficient immunity for protection against BVDV infection (both maternal immunity and immunity acquired through vaccination with triple administration) were also the same as those observed in the previous study.