@article{oai:rakuno.repo.nii.ac.jp:00000547,
 author = {森田, 茂 and 島田, 泰平 and 松岡, 洋平 and 干場, 信司},
 issue = {3},
 journal = {日本家畜管理学会誌・応用動物行動学会誌, Animal Behaviour and Management},
 month = {Sep},
 note = {Article, 毛刈り後の顔見知り個体の外貌の変化がヒツジの群内における敵対行動頻度に及ぼす影響を調べた。1群7頭のサフォーク種ヒツジを2群供試した。A群は7頭の雌(4.9±1.9歳),B群は4頭の雌と3頭の去勢雄(4.4±1.8歳)で構成された。各群の社会的安定性を確認する予備実験として,1日2時間ずつ4日間,敵対行動(闘争,頭突き,追撃,頭振り,威嚇,逃避,回避)を記録した。各群とも,毛刈り前,毛刈り直後,毛刈りの1日後,1.5ヵ月後に2時間観察した。はじめに,各群のヒツジを1頭ずつ4時間繋留した。そして,それらの供試ヒツジを同時に放した後一群として,2時間連続観察し(毛刈り前の観察),敵対行動を記録した。この観察の後に,各群2頭を除き,すべての供試ヒツジを毛刈りした。毛刈りした供試ヒツジ,毛刈りされなかった供試ヒツジともに,毛刈り前の観察と同様の方法で繋留し,敵対行動を再び一緒にした直後,1日後,1.5ヵ月後に観察した。予備実験において,各群で観察された敵対行動は非物理的敵対行動であり,社会的に安定していたと考えられた。本実験においては,各群ともに毛刈り直後の敵対行動頻度は毛刈り前と比べて有意に増加した(P<0.01)。A群における毛刈り1日後の敵対行動頻度は,毛刈り前と同程度になった。しかし,B群の毛刈り1日後における敵対行動頻度は,毛刈り直後よりは少なかったものの (P<0.01),毛刈り前よりは多かった(P<0.01)。以上より,毛刈りは顔見知り個体間の認知を短期間,混乱させることが明らかとなった。We investigated the influence of shearing and a change in appearance on the frequency of agonistic behaviour among sheep flocks. Two groups of 7 Suffolk sheep were studied. Flock A consisted of 7 ewes (4.9±1.9 years old) and Flock B consisted of 4 ewes and 3 wethers (4.4±1.8 years old). As a pre-experiment to confirm the stability in each flock, agonistic behaviour (fighting, head butting, charging, head throw, threat, escape and avoidance) was recorded continuously for 2 hours every day for 4 successive days. Each flock was observed for 2 hours before, immediately, 1 day after and 1.5 months after shearing. At first, sheep in each flock were tethered individually for 4 hours. They were then released simultaneously, and were observed continuously for 2 hours (before shearing), and their agonistic behaviour was recorded. After these observations, all except two sheep from each group were sheared. The sheared and non-sheared sheep were treated as before, and the agonistic behaviour in the flock was observed for 2 hours immediately after being reunited, after 1 day and after 1.5 months. In the pre-experiment, the observed agonistic behaviour of each flock was found to be of the non-physical type, and each flock was considered socially stable. During the experiments, a significant increase in the frequency of agonistic behaviour in each flock was observed immediately after shearing compared with that before shearing (P<0.01). The frequency of agonistic behaviour 1 day after shearing in Flock A was the same as that before; whereas the frequency of agonistic behaviour 1 day after shearing in Flock B was less than that observed immediately after shearing (P<0.01), although it was still more than that observed before shearing (P<0.01). These results indicate that shearing can affect and lead to discrimination in the same flock over a short period of time.},
 pages = {220--227},
 title = {起伏測定装置を用いた飼料高測定と給与飼料の形状変化},
 volume = {44},
 year = {2008}
}