1. Department of Animal Sciences, Reproductive Biology Research Unit, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
2. Department of Anatomy Physiology and Pharmacology, Faculty of Veterinary Medicine, Bogor Agricultural University, Bogor 16680, Indonesia.
3. Research Support Center, Swine and Poultry Feeding Management Laboratory, National Institute of Livestock and Grassland Science, Tsukuba, Ibaraki, Japan.
4. Department of Animal Reproduction, Faculty of Veterinary Medicine, Gadjah Mada University, Yogyakarta 55281, Indonesia.
5. Laboratory of Animal Reproduction, School of Veterinary Medicine, Azabu University, Sagamihara, Kanagawa, Japan.