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

尽管几十年来的研究旨在将攻击最小化，但对许多物种的管理动物来说，攻击是一个主要和常规的挑战。攻击性也会影响野生种群的健康、生存和适应性。激烈的比赛会造成身体（如受伤）、情感和精力上的损失。在激烈的竞争中，个人付出的代价差别很大，不管他们是赢是输。有些人可以以最小的成本快速解决纠纷。它们实现这一目标的机制是未知的，在我们了解它之前，减少侵略的福利惩罚将是困难的。我们的目标是确定a)技能是否有助于比赛的解决，从而降低比赛成本，以及(b)如果是这样，在商业环境中，是否可以操纵畜牧业来促进技巧的战斗，降低比赛成本，提高福利和生产。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经历了严重的侵略。一个大型实验将满足以下所有目标：描述和量化比赛中进攻和防守的技巧。确定社会发展环境和比赛经验对技能的影响。评估社会认知能力和评估策略对技能的贡献。量化技能和传统的战斗能力和侵略性之间的关系。确定竞赛技能是否在商业现实场景中降低了侵略的福利成本竞赛要求使用复杂的行为。技巧在人类运动竞赛中是有影响的，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被研究过。最近的一个框架提出，竞赛技能包括高效、准确、精确和适当的行为执行。我们将测试这个框架，并通过其对比赛成功和成本的影响来量化技能（目标1）。与商业相关的早期战斗经验和最小伤害比赛经验的变化将测试它们对后来的比赛技能的影响（实验对象2）。动物的行为必须以迅速而明智的决定为基础，这就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，一个特定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的能量后，个体就会放弃。在第二类，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，但它可以让动物迅速从可能输掉的战斗中撤退，并大大减少付出的代价。因此，实验3将测试认知能力和个人对评估策略的使用是否会促进适当和有效的行为所反映的技能。在这样做的过程中，我们在个体动物水平上提供了第一个量化的评估策略。目标4还将量化在其他决定战斗能力的因素（如体重）上的优势和好斗的性格是否会提高或抑制技能。至关重要的是，该项目还具有应用相关性。项目2将告知管理层如何在二元竞赛中提高技能。重要的是，在Obj. 5中，猪将以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能提高现实场景中的福利。

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.