1. Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
2. Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
3. Miho Training Center, Japan Racing Association, Ibaraki 300-0415, Japan
4. Department of Clinical Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
5. Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan