1. Shimane Prefectural Federation Agricultural Mutual Aid Association, 748-1 Watarihashi, Izumo, Shimane 693-0004, Japan
2. Joint Department of Veterinary Medicine, Faculty of Agriculture, Tottori University, 4-101 Koyama-Minami, Tottori, Tottori 680-8553, Japan
3. Laboratory of Clinical Pathology, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima, Kagoshima 890-8580, Japan
4. Department of Health Sciences and Technology, Faculty of Health Sciences, Hokkaido University, N12-W5 Kitaku, Sapporo, Hokkaido 060-0812, Japan