ABSTRACT

It is widely acknowledged that environmental enrichment can improve animals’ welfare and emotional state. This study used cognitive bias and response to a novel object to assess the effect of enriched housing on emotional state in sheep. Eighteen sheep were trained to discriminate between high-quality and low-quality reward locations using a go/go task. Sheep were allocated to a housing treatment (enriched or standard) for three weeks. Judgment bias tests were conducted using three ambiguous, unrewarded locations across three days, followed by assessing responses to a novel object. Effects of anxiety levels shown in training on responses to ambiguous locations and to the presence of a novel object were assessed. Enriched-housed sheep tended to have shorter latencies to approach ambiguous positions than standard-housed sheep (P = 0.08), particularly to the near and middle locations. Sheep from standard housing tended to have shorter latencies to approach food with the novel object present than sheep from enriched hosing (P = 0.06). This study shows that enrichment can affect emotional state and that go/go tasks can be successful in sheep and should be considered in future studies of emotional state.

摘要

人们普遍认为，丰富环境可以改善动物的福利和情绪状态。本研究使用认知偏差和对新对象的反应来评估丰富的住房对绵羊情绪状态的影响。对 18 只羊进行了训练，以使用 go/go 任务区分高质量和低质量的奖励位置。绵羊被分配到三周的住房治疗（丰富或标准）。判断偏差测试是在三天内使用三个模棱两可的、没有奖励的位置进行的，然后评估对一个新物体的反应。评估了训练中显示的焦虑水平对模糊位置和新物体存在的反应的影响。与标准圈养羊相比，圈养圈养羊接近模糊位置的潜伏期更短（P = 0.08），尤其是靠近和中间的位置。来自标准住房的绵羊往往比来自富集软管的绵羊具有更短的潜伏期来接近存在新物体的食物（P = 0.06）。这项研究表明，丰富可以影响情绪状态，并且 go/go 任务可以在绵羊身上取得成功，应该在未来的情绪状态研究中加以考虑。