Just ten minutes in the ‘rollkur’ position is all it takes before horses begin to show acute stress responses according to a new study by researchers from the Utrecht University in collaboration with the Danish University of Aarhus. The findings were put forward at an equitation conference in Scotland.
The position, also commonly known as hyperflexion or “low deep and round”, was studied on fifteen Danish dressage horses training routinely at medium to Grand Prix level.
Other common head and neck positions were also studied during a 10 minute time span of walk, trot and canter with the experiments lasting three days in all. Aspects such as heart rate, salivary cortisol concentration, behavior and rein tension were measured during each session.
“This study is the first to test whether there is an acute stress response to the hyperflexed head and neck position in horses ridden in a typical training environment,” Dr Machteld van Dierendonck, from Utrecht University, told the conference, organised by the International Society for Equitation Science.
“We found that the increase in salivary cortisol concentrations from baseline were significantly higher after 10 minutes of riding in the hyperflexed position than the increases observed in the competition head position or with the loose frame.”
Cortisol is known as the stress hormone which can be quantified to measure stress responses in animal welfare studies.
“We didn’t find any significant differences in heart rate, and heart rate variability between the treatments, but we did find that certain behaviours were higher during hyperflexed riding than the other head positions.
“Rein tension during the hyperflexed and competition head position was significantly greater than during the loose frame position.
“Compared to previous studies which have used side reins to maintain the hyperflexed position, the low, deep and round position in this study was less hyperflexed.” she said.
“We wanted to test the horses’ response to this method in a typical training environment.
“Within the parameters of this training situation, we found that the use of the hyperflexed head position, even in horses routinely ridden this way could result in a physiological stress response as measured by salivary cortisol concentrations.
“Interestingly, riders indicated a loss of balance and steering control in the loose frame.”
The study was initiated by Mirjam van Dalum and Mandy Beekmans, joint researchers on the study.