Determining how cognitive ability and affective state impact assessment strategies during aggressive contests to improve pig welfare after regrouping

确定认知能力和情感状态如何影响攻击性竞赛期间的评估策略，以改善重组后猪的福利

• 批准号: BB/T001046/1
• 负责人: Simon Turner
• 金额: $ 58.42万
• 依托单位: Scotland's Rural College
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FT001046%2F1
• 关键词: Determining; how; cognitive; ability; affective

SummaryGlobally one billion pigs are slaughtered annually and most pigs in the UK and EU are raised in intensive indoor systems. Regrouping of unfamiliar pigs is common practice and occurs several times during a pig's life. This sudden mixing of unfamiliar pigs is a major animal welfare concern. The social structure of domestic pigs is based on a dominance hierarchy. In the wild, migration between social groups occurs gradually, and hierarchies are formed with minimal aggression. In contrast, when pigs are mixed into new groups (regrouped) under commercial conditions, dominance hierarchies are formed through vigorous fighting, with many pigs receiving 100 or more skin scratches caused by biting. Increased risk of infection, and reduced weight gain also occur. This proposal aims to address the problem of regrouping aggression in pigs but it is expected to be of benefit in understanding aggressiveness in a wide range of species.Great variation exists in aggressiveness between individual pigs. At present we know little about the causes of this variation and therefore cannot prevent the expression of extreme aggression. Aggressive contests demand that animals make rapid and well-informed decisions, which requires that they assimilate and process complex information and turn it into knowledge (a skill termed cognitive ability). The mood of an animal before an aggressive encounter also likely determines its aggressive behaviour and the emotional response to winning or losing an encounter likely affect its subsequent aggressiveness. However, although cognitive ability and emotional state probably contribute substantially to differences between individuals in their aggressive behaviour and the injuries they receive, this has never been tested in any species. Here we quantify the importance of these factors in the behaviour shown during contests. In the field of behavioural ecology, understanding of contest behaviour has benefitted greatly from the use of theoretical models that are based on particular information gathering rules. Two classes of model have been developed that differ in the strategies used during contests. In the first class, termed self assessment, animals make fight decisions based purely on their own fighting ability and stamina, without reference to the fighting ability of an opponent. After a threshold amount of energy has been spent on fighting, the individual will give up. In the second class of model, termed mutual assessment, animals self assess but also use information about the fighting ability of an opponent. Although more complex, it has greater benefits as an animal can quickly withdraw from a fight it is likely to lose and substantially reduce the amount of injuries. This project tests the hypotheses that (i) cognitively advanced pigs win encounters and make greater use of mutual assessment with reduced injuries from fights; (ii) that a positive emotional state before a fight inflates the animal's view of its own fighting ability and buffers the effect of defeat; and (iii) that losing a fight has a more negative effect on the emotional state of an aggressive pig than a less aggressive one and this emotional response influences later aggressiveness. Finally, we will regroup pigs in a commercially-realistic way (groups of 12 animals) to test whether cognitive ability determines contest costs in the real world. Here we expect that a cognitively advanced pig is able to minimise fight costs to itself and others whilst suffering no penalty in dominance. Throughout, the project will maximise variation in cognitive ability and emotional state by varying the amount of early-life social and physical enrichment the animals receive. We will therefore test whether reductions in the costs of aggression as a result of enhancing cognitive ability and emotional state can be stimulated by management changes. If so, translating these messages to industry could benefit the majority of commercially produced pigs.

全球每年屠宰10亿头猪，英国和欧盟的大多数猪都在密集的室内系统中饲养。将不熟悉的猪重新分组是常见的做法，在猪的一生中会发生几次。这种不熟悉的猪的突然混合是一个主要的动物福利问题。家猪的社会结构是建立在统治等级的基础上的。在野外，社会群体之间的迁移是逐渐发生的，等级制度是以最小的侵略性形成的。相比之下，当猪在商业条件下被混入新的群体（重新分组）时，通过激烈的战斗形成了统治等级，许多猪因咬伤而受到100或更多的皮肤抓伤。感染的风险增加，体重增加减少也会发生。这项建议旨在解决重新分组猪的攻击性的问题，但它预计将有助于了解广泛的物种的攻击性。个体猪之间的攻击性存在很大差异。目前，我们对这种变异的原因知之甚少，因此无法阻止极端攻击性的表达。攻击性的竞争要求动物做出迅速和明智的决定，这要求它们吸收和处理复杂的信息，并将其转化为知识（一种称为认知能力的技能）。动物在遭遇攻击前的情绪也可能决定其攻击行为，而对输赢的情绪反应可能会影响其随后的攻击性。然而，尽管认知能力和情绪状态可能对个体之间的攻击行为和所受伤害的差异有很大影响，但这从未在任何物种中得到过测试。在这里，我们量化这些因素在比赛中表现出的行为的重要性。在行为生态学领域，对竞赛行为的理解大大受益于基于特定信息收集规则的理论模型的使用。已经开发了两类模型，它们在比赛中使用的策略不同。在第一类中，称为自我评估，动物纯粹基于自己的战斗能力和耐力做出战斗决定，而不考虑对手的战斗能力。在战斗中消耗了一定量的能量后，个体就会放弃。在第二类模型中，称为相互评估，动物自我评估，但也使用有关对手战斗能力的信息。虽然更复杂，但它有更大的好处，因为动物可以迅速退出可能失败的战斗，并大大减少受伤的数量。这个项目测试的假设，（一）认知先进的猪赢得遭遇战，并更多地利用相互评估，减少受伤的战斗;（二）积极的情绪状态之前的战斗膨胀的动物的看法，自己的战斗能力和缓冲的影响失败;以及（iii）与攻击性较低的猪相比，战斗失败对攻击性猪的情绪状态有更大的负面影响，这种情绪反应会影响后来的攻击性。最后，我们将以一种商业上现实的方式（12只动物一组）重新分组猪，以测试认知能力是否决定真实的世界中的竞赛成本。在这里，我们期望认知先进的猪能够最大限度地减少自己和其他人的战斗成本，同时不会受到优势的惩罚。在整个过程中，该项目将通过改变动物获得的早期社会和身体丰富程度，最大限度地提高认知能力和情绪状态的变化。因此，我们将测试是否减少侵略的成本，提高认知能力和情绪状态的结果可以刺激管理的变化。如果是这样的话，将这些信息转化为工业可以使大多数商业化生产的猪受益。

项目成果

Third-party intervention and post-conflict behaviour in agonistic encounters of pigs (Sus scrofa).

• DOI: 10.1186/s12983-023-00508-w
• 发表时间: 2023-08-17
• 期刊: FRONTIERS IN ZOOLOGY
• 影响因子: 2.8
• 作者: Maffezzini, Nicole;Turner, Simon P.;Bolhuis, J. Elizabeth;Arnott, Gareth;Camerlink, Irene
• 通讯作者: Camerlink, Irene

Bridging Research Disciplines to Advance Animal Welfare Science: A Practical Guide

桥接研究学科以推进动物福利科学：实用指南

• 发表时间: 2022
• 作者: Arnott G

Social behavior in farm animals: Applying fundamental theory to improve animal welfare.

• DOI: 10.3389/fvets.2022.932217
• 发表时间: 2022
• 期刊: Frontiers in veterinary science
• 影响因子: 3.2

Once bitten, twice shy: Aggressive and defeated pigs begin agonistic encounters with more negative emotions.

• DOI: 10.1016/j.applanim.2021.105488
• 发表时间: 2021-11
• 期刊: Applied animal behaviour science
• 影响因子: 2.3
• 作者: Oldham L;Arnott G;Camerlink I;Doeschl-Wilson A;Farish M;Wemelsfelder F;Turner SP
• 通讯作者: Turner SP

The interplay between personality and social dynamics

人格与社会动态之间的相互作用

• 发表时间: 2022
• 作者: Khatiwada S