Can the presence of a human or a conspecific reduce stress-related behaviours in goats?

From an ethological perspective, human presence may serve as a potential source of social support for animals facing challenging situations. This may be particularly relevant for animals involved in animal-assisted services, where interactions with different people are an integral part of their work. This study aimed to assess whether the presence of a human, both familiar and unfamiliar, can mitigate goats' behavioural responses to social isolation to a similar extent as the presence of a conspecific. It was also examined whether goats' responses to human presence during isolation depend on their willingness to interact with humans in a home setting (outside the isolation context). Sixteen goats, including five adults (16 or 48 months old) and 11 younger individuals (5-6 months old), comprising 10 males and six females, were subjected to four 5-minute isolation tests, varying in the degree of social isolation: complete isolation (S1), and isolation in the presence of an unfamiliar (S2) or a familiar human (S3), or another goat (S4). Behavioural responses were coded in BORIS software. Additionally, prior to the study, touch tests were conducted to measure the goats' motivation for human interaction. While socially isolated, the goats vocalised intensively, attempted to escape, and displayed locomotor activity. The presence of either a conspecific or a human, whether familiar or unfamiliar, reduced stress-related behaviours of highly socialised goats. No differences were noted in the effect of the support figure. This effect may reflect social buffering, although this cannot be definitely established based on the current study. The absence of differential responses to familiar versus unfamiliar humans may suggest a generalised positive response to humans, likely stemming from prior positive experiences, or simply a lack of distinction between them. Goats that accepted human touch for longer in a home setting vocalised less when isolated in the presence of humans. Hence, willingness to interact with humans may partially predict the influence of humans on goat behaviour during social isolation. No significant differences were found between males and females and between younger and older individuals. These findings suggest that, in highly human-socialised goats, human presence may provide behavioural social support during short-term isolation, regardless of human familiarity. Further studies combining behavioural and physiological measures are needed to confirm this conclusion.