1. Yamagata Prefectural Syonai Livestock Hygiene Division Yamagata Mikawa Japan
2. Graduate School of Life and Environmental Sciences Tsukuba University Tsukuba Ibaraki Japan
3. Institute of Livestock and Grassland Science NARO Tsukuba Ibaraki Japan
4. Awaji Agricultural Technology Center Minamiawaji Hyogo Japan
5. Cooperative Department of Veterinary Medicine Faculty of Agriculture Iwate University Morioka Iwate Japan