1. Division of Animal Resource Production, United Graduate School of Agricultural Science; Gifu University; Gifu Japan
2. Laboratory of Animal Reproduction and Physiology, Faculty of Agriculture; Shizuoka University; Shizuoka Japan
3. Division of Animal Reproduction, Maebashi Institute of Animal Science; Livestock Improvement Association of Japan (LIAJ); Maebashi Japan
4. Department of Animal Science, Faculty of Agriculture; Iwate University; Morioka Japan
5. Laboratory of Animal Reproduction, School of Veterinary Medicine; Kitasato University; Towada Japan