Promoting contest skill to reduce the welfare costs of animal agonistic interactions

尽管数十年来的研究旨在最大限度地减少侵略行为，但侵略行为是许多管理动物物种福利的主要和常规挑战。侵略行为还影响野生种群的健康，生存和健身。激烈的竞争会增加身体（如受伤）、情绪和精力的成本。在激烈的竞争中，无论输赢，个人付出的代价都有很大的差异。有些人可以以最小的成本迅速解决争议。他们实现这一点的机制尚不清楚，在我们理解它之前，减少侵略的福利惩罚将是困难的。我们的目标是确定a）技能是否有助于竞赛解决，从而降低竞赛成本，以及（B）如果是这样，是否可以操纵畜牧业实践，以促进熟练的战斗，降低竞赛成本，提高福利和生产在商业环境中。该项目使用猪，因为它们提供了一个理想的模型系统，因为每年屠宰的10亿头猪中的大多数都有明显的侵略性。一个大型实验将解决以下所有目标：1。描述和量化比赛中的进攻和防守技能2。确定社会发展环境和竞赛经验对技能的影响3.评估社会认知能力和评估策略对技能的贡献4.量化技术和传统的战斗能力和侵略性的措施之间的关系5。确定是否竞赛技能降低福利成本的侵略在商业上现实的竞争要求使用复杂的行为。技能在人类运动竞赛中具有重要影响，但值得注意的是，它在动物攻击性竞赛中的作用几乎完全没有研究。最近的一个框架提出，竞赛技能包括有效，准确，精确和适当的行为执行。我们将测试这个框架，并通过技能对竞赛成功和成本的影响来量化技能（目标1）。在商业相关的早期生活机会中，游戏格斗经验和最小破坏性竞赛经验的变化将检验它们对以后竞赛技能的影响（目标2）。行为必须以迅速和明智的决定为基础，这要求动物吸收和处理复杂的信息，并将其转化为知识（称为认知能力）。认知能力是否能提高技能的行为执行力尚不清楚。在比赛中，一个具体的认知挑战是收集信息，并利用这些信息来决定何时放弃。已经开发了几类信息收集模型。在最简单的自我评估中，动物完全根据自己的战斗能力和耐力做出战斗决定，而不考虑对手的能力。在战斗中消耗了一定量的能量后，个体就会放弃。在第二类中，称为相互评估，动物自我评估，但也评估对手的战斗能力。虽然更复杂，但它允许动物快速退出可能会失败的战斗，并大大降低了所支付的成本。因此，目标3将测试认知能力和个人使用的评估策略是否促进技能，反映在适当和有效的行为。在这样做的过程中，我们提供了第一个量化的评估策略，在个别动物的水平。目标4还将量化在其他决定战斗能力的因素（如体重）和攻击性人格方面的优势是否会增强或抑制技能。至关重要的是，该项目还具有应用相关性。目标2将告知管理者如何在双人竞赛中提升技能。重要的是，在目标5中，猪将以一种商业上现实的方式重新分组（12只动物一组），以测试配对比赛中的技能是否会改善现实世界中的福利。

SummaryAggression is a major and routine challenge to welfare in many species of managed animals despite decades of research aimed at minimising it. Aggression also affects health, survival and fitness in wild populations. Aggressive contests accrue physical (e.g. injuries), emotional and energetic costs. Individuals vary greatly in the costs paid during aggressive contests, irrespective of whether they win or lose. Some individuals can resolve contests quickly with minimal costs. The mechanism by which they achieve this is unknown and, until we understand it, reducing the welfare penalty of aggression will be difficult. Our aims are to determine a) whether skill facilitates contest resolution and thus reduces contest costs, and (b), if so, whether husbandry practices can be manipulated to promote skilful fighting, reduce contest costs and enhance welfare and production in a commercial setting. The project uses pigs as they offer an ideal model system and because most of the one billion pigs slaughtered annually experience significant aggression. One large experiment will address all objectives below:1. Characterise and quantify skill in contest aggression and defence2. Determine the effect of the social developmental environment and contest experience on skill3. Assess the contribution of socio-cognitive ability and assessment strategy to skill4. Quantify the relationship between skill and conventional measures of fighting ability and aggressiveness5. Determine whether contest skill reduces the welfare costs of aggression in a commercially realistic scenarioContests demand the use of complex behaviours. Skill is influential in human sporting contests, yet remarkably its role in animal aggressive contests is almost entirely unstudied. A recent framework has proposed that contest skill comprises efficient, accurate, precise and appropriate behavioural execution. We will test this framework and quantify skill by its effects on contest success and costs (Obj. 1). Variation in commercially relevant early-life opportunities for play fighting experience and minimally-damaging contest experience will test their effects on later contest skill (Obj. 2). Behaviour must be underpinned by rapid and well-informed decisions, which requires that animals assimilate and process complex information and turn it into knowledge (termed cognitive ability). Whether cognitive ability improves the behavioural execution of skill is unknown. A specific cognitive challenge during contests is to gather information and use this to decide when to give up. Several classes of information-gathering model have been developed. In the simplest, termed self assessment, animals make fight decisions based purely on their own fighting ability and stamina, without reference to the ability of an opponent. After a threshold amount of energy has been spent on fighting, the individual will give up. In a second class, termed mutual assessment, animals self assess but also assess the fighting ability of an opponent. Although more complex, it allows an animal to quickly withdraw from a fight it is likely to lose and substantially reduces the costs paid. Hence, Obj. 3 will test whether cognitive ability and individual use of assessment strategy promote skill as reflected in appropriate and efficient behaviour. In doing so we provide the first quantification of assessment strategies at the individual animal level. Obj. 4 will also quantify whether superiority in other determinants of fighting ability (e.g. weight) and an aggressive personality enhance or suppress skill. Crucially the project also has applied relevance. Obj. 2 will inform how management can promote skill in dyadic contests. Importantly, in Obj. 5 pigs will be regrouped in a commercially-realistic way (groups of 12 animals) to test whether skill in paired contests improves welfare in a real-world scenario.