Operationalising social competence and estimating its genetic and genomic basis to improve the welfare of pigs

全球每年有10亿头猪被屠宰，大多数猪的福利因有害的社会行为而减少（例如，10%的猪因打架而被抓伤100多处，咬尾巴会导致断尾和脊柱损伤）。这些行为的管理解决方案成本高昂，限制了其实施。有害的社会行为是猪福利最持久和最常见的挑战之一。然而，猪在它们给予和接受的有害行为的数量上是不同的。这种变异是遗传因素造成的，而反对有害行为的繁殖可以大大改善福利和生产力。然而，孤立的有害行为特征的繁殖效率低下，因为它可能会恶化其他特征。它也没有考虑到积极的社会互动可能在功能性社会关系中发挥的潜在重要作用，而这种作用迄今为止在很大程度上被忽视了。这个项目采取了一种新的方法，探索潜力，繁殖的整体社会能力。在行为生态学中，社交能力是一种更高层次的特征，它来自于社交技能和提高健康（即生存和生殖成功）的行为的结合。因此，一个有社会能力的动物是一个综合社会行为使其适应性最大化的动物。至关重要的是，这一概念允许积极和消极的行为形式影响整体社会能力。此外，它不仅仅是一个孤立行为的列表，而是考虑行为特征之间的关系，以考虑它们对健身的综合影响。有证据表明，社会能力是在自然选择，除了那些个人行为，组成it.This项目使社会能力的概念管理动物的一个新的应用。它将测试两个假设，（一）社会行为特征可以被整合到定义新兴的社会能力，其对福利的影响，以及（二）社会能力是在遗传控制下，可以利用动物育种。我们的目标是创造新的基础知识，并切实为养猪业提供一种方法来定义，测量和培育具有整体社会能力的猪，这些能力已被证明对福利有益。PIC是世界上最大的猪育种公司，也是该项目的合作伙伴，这将确保结果的快速商业转化。SRUC猪研究农场的目标1将通过在断奶前增加一半的猪的社会经验，最大限度地提高社会能力的可能变化。接下来，我们将在对比鲜明的环境中饲养猪，并测量广泛的社会行为和福利结果。统计模型将描述社会行为如何结合联合收割机来解释福利结果的最大变化，从而哪些行为套件定义了社会能力。目标2将在SRUC单位和PIC育种场进行，这两个单位的环境不同，但使用相同的公猪。将记录目标1中所示的构成社交能力的社交行为。这将量化（i）社会能力的遗传决定，（ii）环境对遗传倾向表达的影响，以及（iii）为提高社会能力而进行育种的经济结果。社会能力在任何物种中都没有得到很好的表征，我们希望我们对这个概念的新颖使用能够引起广泛的兴趣。它将加强对行为如何相互作用以及积极社会行为在福利方面的作用的理解，而这方面所知甚少。从未有人研究过繁殖的潜力，以获得理想的行为组合，包括亲社会行为。使工业具备繁殖一种性状的能力，这种性状有效地结合了几种社会行为的相互作用，并明显改善了福利，这可能使大多数商业化生产的猪受益。

SummaryGlobally one billion pigs are slaughtered annually and most experience reduced welfare from harmful social behaviours (e.g. 10% of pigs gain more than 100 scratches from fighting and tail biting can cause tail amputation and spinal abscesses). Management solutions to these behaviours are costly which limits their implementation. Harmful social behaviours are one of the most persistent and routine challenges to pig welfare. However, pigs differ in the amount of harmful behaviour they give and receive. There is a genetic contribution to this variation and breeding against expression of harmful behaviours could greatly improve welfare and productivity. However, breeding on isolated harmful behavioural traits is inefficient as it could worsen other traits. It also fails to account for the potentially major role that positive social interactions may play in functional social relationships that has so far largely been ignored. This project takes a new approach by exploring the potential to breed for overall social competence. In behavioural ecology, social competence is a higher level trait that emerges from the combination of social skills and behaviours that improve fitness (i.e. survival and reproductive success). A socially competent animal is therefore one whose combined social behaviour maximizes its fitness. Crucially, the concept allows positive and negative forms of behaviour to affect overall social competence. Additionally, it is more than simply a list of isolated behaviours, but instead accounts for the relationships between behavioural traits to consider their combined effect on fitness. There is evidence that social competence is under natural selection, in addition to those individual behaviours that comprise it. This project makes a novel application of the social competence concept to managed animals. It will test two hypotheses that (i) social behavioural traits can be integrated to define emergent social competence identifiable by its effects on welfare and (ii) that social competence is under genetic control that can be exploited in animal breeding. Our aim is to both create new basic knowledge and to practically equip the pig breeding industry with a way to define, measure and breed for pigs with an overall social ability that has evidenced benefits for welfare. PIC is the largest pig breeder in the world and a partner in this project which will ensure rapid commercial translation of the results.Objective 1 on SRUC's pig research farm will maximise likely variation in social competence by giving half of the pigs increased social experience before weaning. Next we will house pigs in contrasting environments and measure a broad range of social behaviours and welfare outcomes. Statistical modelling will describe how social behaviours combine to explain maximum variation in welfare outcomes and hence which suites of behaviours define social competence. Objective 2 will occur at the SRUC unit and a PIC breeding farm which differ in environments but will use the same sires. The social behaviours shown in Objective 1 to constitute social competence will be recorded. This will quantify (i) the genetic determination to social competence, (ii) the effect of the environment on expression of genetic predisposition, and (iii) the economic outcomes of breeding for enhanced social competence. Social competence has been poorly characterised in any species and we expect our novel use of the concept to be of broad interest. It will enhance understanding of how behaviours interact and the role of positive social behaviours in welfare, of which very little is known. The potential to breed for desirable combinations of behaviours, including pro-social ones, has never been studied. Equipping industry with the ability to breed for a trait that efficiently combines the interactive effects of several social behaviours and that demonstrably improves welfare could benefit the majority of commercially produced pigs.