1. Laboratory of Farm Animal Medicine, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
2. Beef Cattle Research Center, Ibaraki Prefecture, Ibaraki, Japan
3. Veterinary Medical Center, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
4. Laboratory of OSG Veterinary Science for Global Disease Management, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
5. Laboratory of Veterinary Pathology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan