1. Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
2. NOSAI-Hidaka-Tobu, Hokkaido 057-0033, Japan
3. Hidaka Horse Breeders’Associtaion, Hokkaido 057-0024, Japan
4. Equine Science Division, Hidaka Training and Research Center Japan Racing Association, Hokkaido 057-0171, Japan