1. The Horse Racing School, Japan Racing Association, Chiba 270-1431, Japan
2. United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
3. Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
4. Miho Training Center, Japan Racing Association, Ibaraki 300-0493, Japan
5. Equine Research Institute, Japan Racing Association, Tochigi 320-0856, Japan
6. Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan
7. Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
8. Shadai Corporation, Hokkaido 059-1432, Japan