1. Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
2. Division of Animal Science, University of Missouri, MO 65211, U.S.A.
3. Shadai Corporation, Hokkaido 059-1432, Japan
4. United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
5. Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
6. Department of Veterinary Pathology, Rakuno Gakuen University, Hokkaido 069-8501, Japan
7. Cooperative Division of Veterinary Sciences (Doctoral Program), Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan