Abstract: The present study aims to investigate whether the presence of unrelated adult horses at weaning would reduce the social stress of weaning and the emergence of undesirable behaviours. We tested this hypothesis in 32 domestic foals by comparing short and medium term behavioural and physiological responses to weaning in foals maintained in homogeneous groups of peers (PW) to those of foals grouped with both peers and unrelated adults (AW). In total, three trials were conducted, which each trial consisting of one AW group and one PW group. In all foals, weaning was followed by increased vocalization, increased locomotion and increased salivary cortisol concentration. However, signs of stress were less pronounced and shorter in duration in weanlings housed with unrelated adults (e.g. whinnies: p < 0.05; salivary cortisol: p < 0.05). Only foals without adults exhibited increased aggressiveness towards peers (p < 0.05) and abnormal behaviours (p < 0.05) such as excessive wood-chewing and redirected sucking towards peers. In conclusion, introducing adults to minimize weaning stress in foals and later on aggressiveness and abnormal behaviours appears as the most promising approach to date.

Abstract: Weaning foals marks a stressful event in horses' lives. Limited research exists regarding different housing methods post-weaning and the long-term implications on horse behavior and welfare. The purpose of this study was to monitor behavior and physiological stress markers in horses weaned individually in solid partition box stalls versus horses weaned in small groups and housed in paddocks. Both treatment groups underwent maternal deprivation stress, but the stalled weanlings had the additive effects of social isolation which prevented them from performing social behaviors. Quarter Horse weanlings from the Michigan State University, Merillat Equine Center, average age 4.5 months, were weaned in 13.4 m2 box stalls (n=6) or in groups of three in a 992 m2 paddock, which had very limited grazing forage and an open shelter available (n=6). Subjects were fed concentrate and hay to National Research Council recommendations. A time budget for 31 observed behaviors was developed. Behavioral observations were made 2 days per week, approximately 6 h per day, for the duration of the 56 days study. Instantaneous samples were recorded every 5 min on each observation day, with equal division between the two treatment groups (n=35 scans per horse per observation day). Focal data were recorded continuously between scans to provide a more detailed ethogram. On each observation day, fecal samples were collected to measure 11,17-dioxoandrostanes, an indicator of glucocorticoid metabolite concentration. Regarding the fecal 11,17-dioxoandrostanes, there was no discernible treatment difference either immediately post-weaning or at the conclusion of the 56 days study. Interestingly, all 12 weanlings showed a 4 week post-weaning increase in 11,17-dioxoandrostanes. The reason for this peak was unclear. Behavioral observations demonstrated a significantly different time budget in paddock-housed weanlings than in stall-housed weanlings (P<0.0001). Paddock-housed weanlings displayed a time budget more like a feral horse time budget, showing more time spent moving and less time spent lying. Paddock-housed weanlings, who had the option of selectively engaging in a broader range of behaviors, showed strong motivation to graze and be near conspecifics. Stalled weanlings spent significantly more time engaged in aberrant behaviors: licking or chewing the stall/shed wall, kicking at the stall/shed wall, pawing, and bucking/rearing bouts (P<0.03). Based on the variety of behaviors shown, the ability to engage in strongly preferred behaviors, and freedom from aberrant behavior, we conclude that the paddock-reared, group-housed weanlings had better welfare. However, there was insufficient evidence to conclude that the stalled weanlings had poor welfare.

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.