1. Department of Veterinary Medicine, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan
2. Chemical Division, Enuchicken Co., Ltd., 3669 Kori Chiran-cho Minamikyushu-shi, Kagoshima 897-0302, Japan
3. Department of Veterinary Medicine, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan