Investigating equine behaviour differences between alternative grazing systems

Introduction: Modern management practices can restrict natural behaviours for horse and human health, safety, convenience and ease of management (Noble, 2023). Behaviours such as social interactions and foraging have been observed throughout generations of feral and domesticated horses and the repercussions of management practices can negatively impact the mental, emotional and physical state of the horse. Excessive stabling and social isolation have been linked to stereotypic behaviours and diet-related health issues (Burla et al., 2016). Track grazing systems were developed with the intention of returning the domestic horse to a more naturalistic environment. Providing the ability to engage with conspecifics, roam constantly with ad libitum forage and a low risk of weight-related issues, offering a potential solution to the prevalence of equine obesity, isolation and stress (Jackson, 2006). The aim of this study is to compare differences in behaviours between groups of horses on track grazing systems and traditional open paddocks.
Materials and Methods: This longitudinal study utilised an ethogram to identify positive, neutral and negative social and foraging behaviours for each grazing system. The study monitored a total of 19 horses allocated to their respective grazing system according to weight and health requirements. Behaviours were recorded in 10-minute observations of each herd twice weekly between the months of July to October (2023), resulting in 37.5 hours of logged observations. The ethogram used for observation was developed and approved by HorseWorld staff for regular use in assessments and observations of their equine population. One-zero sampling was implemented to record behaviours and correlation tests were conducted using IBM SPSS V29.0. A statistically significant relationship between behaviours displayed on track grazing systems and traditional open paddocks was evaluated using a Mann-Whitney U test.
Results: Horses in paddocks showed more agonistic and alert behaviours (76.92% of total Resource Guarding behaviours observed and 68.18% of total Hyper Responsive behaviours observed) whereas horses on track systems displayed a higher number of comfort and positive social behaviours (83.33% of total Rolling observed and 73.87% of total Allo-grooming observed). However, there were no significant differences in any behaviours observed between grazing systems (p>0.05).
Discussion and Conclusions: While there was no statistical significance between behaviours found between grazing systems, results tentatively show that paddock-based horses displayed behaviours suggesting a hypersensitivity to external stimuli and a lack of cohesion in the group while track system-based horses exhibited behaviours suggesting successful rank establishment and stronger bonds in the herd. There is a lack of research and evidence behind the impact of track systems on the horse’s physical or psychological wellbeing, which may present negative implications for welfare. This necessitates further study comparing natural behaviours displayed in feral and domestic horses in alternative management environments in order to discover their impact and develop management regimes that optimise equine welfare.