1. Nanbu Livestock Hygiene Service Center, 324-2 Bo, Saida-machi, Kanazawa, Ishikawa 920-3101, Japan
2. Ishikawa Agriculture and Forestry Research Center, Livestock Experiment Station, 93-2 Na, Tsuboyama, Houdatsushimizu, Hakui, Ishikawa 929-1325, Japan
3. Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
4. The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan