Release from restraint generates a positive judgement bias in sheep
Release from restraint generates a positive judgement bias in sheep
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DOI：
10.1016/j.applanim.2009.11.003
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发表时间：
2010-01-15
影响因子：
2.3
通讯作者：
Lee, Caroline
中科院分区：
文献类型：
--
作者：
Doyle, Rebecca E.;Fisher, Andrew D.;Lee, Caroline
对动物判断偏差的研究引起了人们的兴趣，因为它可以通过检测动物对环境的悲观或乐观评估来潜在地测量情绪状态。虽然在实验室物种中已经成功地发现了判断偏差，但在牲畜物种中还没有此类研究的报道。20只母羊被训练去学习一项空间定位任务，该任务要求根据围栏中桶的位置做出去或不去的反应。一个桶的位置与饲料奖励有关，另一个与负强化因素有关（没有食物和狗的展示）。10只羊连续3天进行6 h的约束和隔离应激（RIS）。在每天的RIS之后，通过测量它们对三个以前未见过的桶位置和学习过的位置的反应，测试所有羊的判断偏差。血清皮质醇、血液学参数和羊在野外测试中的行为也被记录下来。与对照羊相比，受约束和隔离的羊更有可能接近模棱两可的桶位置（P = 0.008），这表明ris治疗的动物具有更乐观的判断偏差。尽管血清皮质醇浓度显示绵羊在RIS处理后处于高度应激状态（P = 0.019）。这一发现提供了证据，证明有可能测量牲畜物种的判断偏差。当从RIS中释放出来时，羊可能比对照组的羊表现出更积极的情绪状态，或者更少的风险感知。爱思唯尔B.V.版权所有
The study of judgement biases in animals has attracted interest as a way of potentially measuring emotional states by being able to detect pessimistic-like or optimistic-like evaluations of their environment. While judgement biases have been successfully identified in laboratory species, no such research has been reported in livestock species. Twenty ewes were trained to learn a spatial location task that required a go/no-go response according to the location of a bucket in a pen. One bucket location was associated with a feed reward, and the other associated with a negative reinforcer (no food and the presentation of a dog). Ten sheep were then subjected to a 6 h restraint and isolation stress (RIS), for three consecutive days. Following RIS on each day, all sheep were tested for biases in judgement by measuring their response to three previously unseen bucket locations and the learnt locations. Serum cortisol, haematological parameters, and behaviour of the sheep in an open field test were also recorded. Restrained and isolated sheep were more likely to approach the ambiguous bucket locations compared to control sheep (P = 0.008), suggesting RIS-treated animals had a more optimistic-like judgement bias. This was despite serum cortisol concentrations showing that sheep were highly stressed by the RIS treatment (P = 0.019). This finding provides evidence that it is possible to measure judgement biases in a livestock species. When released from RIS the sheep may have had a more positive emotional state, or a lesser perception of risk, than that exhibited by control sheep. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.