Maebashi Institute of Animal Science, Livestock Improvement Association of Japan, Inc., 316 Kanamaru, Maebashi, Gunma, 371-0121, Japan. onogi@liaj.or.jp|Maebashi Institute of Animal Science, Livestock Improvement Association of Japan, Inc., 316 Kanamaru, Maebashi, Gunma, 371-0121, Japan. onogi@liaj.or.jp|Maebashi Institute of Animal Science, Livestock Improvement Association of Japan, Inc., 316 Kanamaru, Maebashi, Gunma, 371-0121, Japan. onogi@liaj.or.jp