1. Yakult Central Institute for Microbiological Research, 1796 Yaho, Kunitachi, Tokyo 186-8650,1
2. School of Veterinary Medicine and Animal Sciences, Kitasato University, Towada, Aomori 034-8628,2 and
3. The Japan Bloodhorse Breeder's Association Kagoshima Stallion Station, 3995 Nogata, Oosaki, Oso, Kagoshima 899-8313,3 Japan