Heart rate variability after horse trekking in leading and following horses.

This research investigates whether leading and following horses experience different stress levels during horse trekking (HT) by analyzing heart rate variability (HRV) and found that the leading horse tends to have a higher stress response.

Research Objective

• The researchers sought to offer insight into the physical effects of HT on horses. They began with a specific hypothesis, suggesting that horses which lead during these exercises might experience a greater degree of stress, as they encounter potential stressors in the forefront of the activity.

Study Design and Methods

• The study involved six horses, which were subjected to 15 minutes of ground riding followed by 45 minutes of HT, involving a mix of walking and trotting.
• Heart rate variability of the horses was assessed at three specific intervals after exercise – 30, 60, and 90 minutes. This was done as a means to measure the horses’ stress response to the exercise.
• The heart rate variability was monitored and analyzed for each horse, with particular attention paid to the high frequency / low frequency power band of the heart rate variability, which is an index of sympathetic nervous activity (a function of the body related to stress response).

Results

• There did not seem to be a significant difference in heart rate during the exercise between leading and following horses. This suggested that the act of exercise itself did not have varying effects on the horses based on their position within the trekking group.
• However, after the exercise, a trend seemed to emerge, where the leading horses demonstrated a higher high-frequency/low-frequency power band in their heart rate variability. Being slightly above statistical significance (P < 0.1), it indicates a potential disparity in the stress response of leading and following horses, with leading horses experiencing higher stress.

Conclusion

• The study suggests that although the heart rates during exercise did not differ significantly between leading and following horses, the post-exercise period showed a perceptible difference, implying that the leading horse might be in a higher stressed state than the following horse after HT.