1. Joint Graduate School of Veterinary Sciences, Yamaguchi University, Yamaguchi 753-8515, Japan
2. Division of Animal Husbandry, Faculty of Veterinary Medicine, Airlangga University, Surabaya 60115, Indonesia
3. Department of Mathematics Education, Faculty of Teacher Training and Education, Sebelas Maret University, Surakarta 57126, Indonesia
4. Ohita Agricultural Mutual Aid Association, Taketa 878-0024, Japan
5. Faculty of Fisheries, Kagoshima University, Kagoshima 890-0056, Japan
6. Joint Faculty of Veterinary Medicine, Kagoshima University, Kagoshima 890-0065, Japan
7. Laboratory of Theriogenology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan