Abstract: The EU-funded Animal Welfare Indicators (AWIN) research project (2011-2015) aimed to improve animal welfare through the development of practical on-farm animal welfare assessment protocols. The present study describes the application of the AWIN approach to the development of a welfare assessment protocol for horses (Equus caballus). Its development required the following steps: (i) selection of potential welfare indicators; (ii) bridging gaps in knowledge; (iii) consulting stakeholders; and (iv) testing a prototype protocol on-farm. Compared to existing welfare assessment protocols for other species, the AWIN welfare assessment protocol for horses introduces a number of innovative aspects, such as implementation of a two-level strategy focused on improving on-farm feasibility and the use of electronic tools to achieve standardised data collection and so promote rapid outcomes. Further refinement to the AWIN welfare assessment protocol for horses is needed in order to firstly gather data from a larger reference population and, secondly, enhance the welfare assessment protocol with reference to different horse housing and husbandry conditions.

Abstract: Social bond analysis is of major importance for the evaluation of social relationships in group housed horses. However, in equine behaviour literature, studies on social bond analysis are inconsistent. Mutual grooming (horses standing side by side and gently nipping, nuzzling, or rubbing each other), affiliative approaches (horses approaching each other and staying within one body length), and measurements of spatial proximity (horses standing with body contact or within two horse-lengths) are commonly used. In the present study, we assessed which of the three parameters is most suitable for social bond analysis in horses, and whether social bonds are affected by individual and group factors. We observed social behaviour and spatial proximity in 145 feral horses, five groups of Przewalskiâ&#65533;&#65533;s horses (N = 36), and six groups of feral horses (N = 109) for 15 h per group, on three days within one week. We found grooming, friendly approaches, and spatial proximity to be robust parameters, as their correlation was affected only by the animalsâ&#65533;&#65533; sex (GLMM: N = 145, SE = 0.001, t = â&#65533;&#65533;2.7, p = 0.008) and the group size (GLMM: N = 145, SE < 0.001, t = 4.255, p < 0.001), but not by the horse breed, the aggression ratio, the social rank, the group, the group composition, and the individuals themselves. Our results show a trend for a correspondence between all three parameters (GLMM: N = 145, SE = 0.004, t = 1.95, p = 0.053), a strong correspondence between mutual grooming and friendly approaches (GLMM: N = 145, SE = 0.021, t = 3.922, p < 0.001), and a weak correspondence between mutual grooming and spatial proximity (GLMM: N = 145, SE = 0.04, t = 1.15, p = 0.25). We therefore suggest either using a combination of the proactive behaviour counts mutual grooming and friendly approaches, or using measurements of close spatial proximity, for the analysis of social bonds in horses within a limited time frame.

Abstract: Social relationships are essential for maintaining human mental health, yet little is known about the brain mechanisms involved in the development and maintenance of social bonds. Animal models are powerful tools for investigating the neurobiological mechanisms regulating the cognitive processes leading to the development of social relationships and for potentially extending our understanding of the human condition. In this review, we discuss the roles of the neuropeptides oxytocin and vasopressin in the regulation of social bonding as well as related social behaviors which culminate in the formation of social relationships in animal models. The formation of social bonds is a hierarchical process involving social motivation and approach, the processing of social stimuli and formation of social memories, and the social attachment itself. Oxytocin and vasopressin have been implicated in each of these processes. Specifically, these peptides facilitate social affiliation and parental nurturing behavior, are essential for social recognition in rodents, and are involved in the formation of selective mother-infant bonds in sheep and pair bonds in monogamous voles. The convergence of evidence from these animal studies makes oxytocin and vasopressin attractive candidates for the neural modulation of human social relationships as well as potential therapeutic targets for the treatment of psychiatric disorders associated with disruptions in social behavior, including autism.