アンケートを併用した隔離試験によるウマの不安傾向の評価(動物行動学) Assessing Equine Anxiety-Related Parameters Using an Isolation Test in Combination with a Questionnaire Survey(Ethology)

ウマの不安傾向を理解することは,騎乗者にとっても獣医師にとっても重要である.本研究では,被験馬をよく知る管理者が気質評価アンケートに回答することで得られた不安傾向スコアと,行動実験から得られた結果とを比較し,不安傾向と関連が深い行動指標を探索した.各馬を新奇環境に導入後,ビニール紐を介して壁に繋留し,管理者が傍にいる状態で2分間観察したのち管理者が離れウマ単独の状態で更に2分間観察した.その結果,単独にされることで多くの観察データが変化したが,アンケート調査により不安傾向が高いと評価された個体ほど,心拍反応が高くビニール紐切断までの潜時は短かった.こうした傾向はメスでより顕著に観察された.以上のことから,新奇環境に単独でおかれた際の心拍数と切断潜時は不安傾向の指標として有効であることが示された.また行動実験と気質評価を組み合わせることで,他の気質項目についてもより信頼性の高い評価を行える可能性が示された.

The aim of the study was to determine parameters reflecting equine anxiety trait by comparing results obtained in a behavior test and an anxiety score assessed by familiar caretakers in response to a questionnaire. In the behavior test, horses were individually led into a novel room by their caretakers and loosely tethered to decrease excessive movement using the common cross-tying technique with two leads and breakable plastic cords. The horses initially remained with their caretaker for 2 min ; the caretaker then left and the subject animal was left alone for 2 min. The latency to break the plastic cords, heart rate, the number of steps and pawings were recorded. When the horses were left alone, most parameters changed significantly and some showed sexual differences. A correlation analysis revealed that anxiety score assessed by caretakers showed a negative correlation with the latency to break the plastic cord and a positive correlation with heart rate only when horses were isolated. These two were suggested feasible parameters for assessing the anxiety trait of unfamiliar horses. Both the behavioral results and the anxiety scores also indicated that females were more anxious than males. Our results suggest that it would be a useful strategy for assessing other temperament traits as well to combine behavior tests with a questionnaire survey.