Effects of Overcheck Use on Stress Parameters and Welfare Implications in Driving Horses.

This research conducted three studies to assess the effects of using overchecks (bridle-to-backpad straps) on horses, with particular focus on stress parameters. The findings suggested that tying horses with high overchecks increased stress levels, but the effects could be reduced with an adaptation period.

Research Structure

• The research was structured in three sequential studies aimed at evaluating the implications of tying horses with different configurations of overchecks.
• The first was an observational study that involved 305 horses which had high overchecks (HC), low overchecks (LC), or no overchecks (NC) with frequencies of 29.2%, 51.8%, and 19.0%, respectively.
• The second part of the research (Study 1) used a Latin square design involving six horses and was composed of a 90-minute tie test (90TT) with treatments. The treatments consisted of HC, LC, and NC across three periods.
• The final part (Study 2) sought to determine whether acclimation to tying with overchecks could reduce the cortisol response that was observed in Study 1. In this phase, six horses were tied for 60 minutes each day over two weeks, followed by a 60-minute TT (60TT).

Key Findings

• In Study 1, horses wearing high overchecks (HC) showed higher levels of plasma cortisol, a stress hormone, compared to those wearing low overchecks (LC) and no overchecks (NC). This suggests that high overchecks contribute to stress in horses.
• Additionally, muscle soreness (MSS) and tightness (MTS) were assessed before and 24 hours after the 90TT and were found to be higher after 24 hours, regardless of the type of check used.
• Study 2 discovered that neither plasma cortisol levels nor heart rate raised above base levels during the 60-minute tie test following the two-week adaptation period. This suggests that if horses have time to adapt to the overchecks and the tying process, their stress levels do not significantly increase.
• Overall, the findings demonstrate that using restrictive high checks appears to be a stressor for horses, but the stress can be mitigated if an adaptation period is provided.