1. Laboratory of OSG Veterinary Science for Global Disease Management, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
2. Beef Cattle Institute, Ibaraki Prefecture of Livestock Research Center, Ibaraki, Japan
3. Ibaraki Prefecture Kenpoku Livestock Hygiene Service Center, Ibaraki, Japan
4. Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
5. Veterinary Medical Center, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan