1. Graduate School of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
2. Department of Theriogenology, Faculty of Veterinary Medicine, Damanhur University, Beheira, Egypt
3. Department of Anatomy, University of Veterinary Medicine Hannover, Hannover D-30173, Germany
4. Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
5. Department of Basic Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan
6. Genetics Hokkaido Association, Hokkaido 089-0103, Japan