@article{oai:repository.naro.go.jp:00001318,
 author = {柴, 伸弥 and SHIBA, Nobuya and 樋口, 幹人 and HIGUCHI, Mikito and 今成, 麻衣 and IMANARI, Mai and 米内, 美晴 and YONAI, Miharu and 東山, 雅一 and HIGASHIYAMA, Masakazu and 渡邊, 彰 and WATANABE, Akira},
 journal = {東北農業研究センター研究報告, Bulletin of TOHOKU Agricultural Research Center},
 month = {Mar},
 note = {We studied optimal body weight gain during the middle fattening stage in Japanese Shorthorn steers in a two-season grazing system. Specifically, body weight gain in steers given access to grazing (n=24 ; grazed group) was compared to that of steers kept in a pen for the entire fattening period (n=29 ; control group)．Body weight gain in all steers was raised on the first, middle and finishing stages. All steers were maintained at the NARO Tohoku Agriculture Research Center from 2004 to 2013. In the experimental group, grazing was allowed during the middle fattening stage. The difference in average body weight between the two groups was a maximum of 62 kg at the middle fattening stage, before recovering to 33 kg by the end of the fattening stage after grazing. These findings indicate that compensatory growth occurred in the grazed group ; this compensatory growth was observed for 4-20 weeks after grazing stopped. When the daily body weight gain of the middle fattening stage was approximately 0.6 kg/day, the largest daily weight gain was observed by fattening stage. Consequently, body weight gain should be maintained at a minimum of 0.6 kg/day in order to avoid the adverse effects of grazing in the middle fattening stage on carcass weight. Although the meat quality between the two groups was not significantly different, a tendency towards reduced carcass weight and an increase in the ratio of meat to carcass weight was observed. The carcasses of grazed steers should be evaluated according to criteria that differ from the conventional Japanese carcass evaluation system., 日本短角種去勢牛を2シーズン放牧に供試し、肥育中期における放牧中の適正な日増体量を検討した。2004～2013年に農研機構東北農業研究センターにて飼養された通年舎飼い牛 (対照区、29頭) と2シーズン放牧牛 (放牧区、24頭) を比較した結果、放牧期間中に両区の平均体重差は最大で62kgとなるが、放牧終了後の肥育により半分程度の33kgまで回復し、肥育後期における代償性発育が確認された。代償性発育は放牧終了後4～20週の約4ヵ月間に認められ、このとき肥育中期の日増体量が約0.6kg/日で、肥育期間中の総増体量が最大となることが示された。したがって、枝肉重量への影響を考慮すると、放牧中の日増体量の目標を0.6kg/日以上として放牧牛の管理を行うべきである。2シーズン放牧は肉質に明らかな差を及ぼさなかったが、枝肉の重量を小さく、枝肉中の赤肉組織割合を大きくする傾向が認められ、従来の枝肉評価基準とは異なる基準で評価されるべきと考えられた。},
 pages = {51--58},
 title = {日本短角種去勢牛の2シーズン放牧肥育における判別品種での反応によるダイズモザイクウイルス日米系統の比較放牧中の適正な増体量},
 volume = {117},
 year = {2015},
 yomi = {シバ, ノブヤ and ヒグチ, ミキト and イマナリ, マイ and ヨナイ, ミハル and ヒガシヤマ, マサカズ and ワタナベ, アキラ}
}