Changes in salivary and plasma cortisol levels in Purebred Arabian horses during race training session.

The research investigates the relationship between physical activity, stress and the release of cortisol in Arabian horses during a race training session. By analyzing saliva samples, researchers demonstrated that cortisol concentrations can serve as an indicator of the workout intensity experienced by the horses.

Objective of the Study

• The main purpose of the research was to use saliva samples in determining cortisol concentrations. This aims to provide a measure of the work-load level in Arabian horses during their race training sessions.

Methods and Procedures

• The study involved twelve Purebred Arabian horses, aged between 3 and 5 years, during their routine training sessions.
• Post warm-up, the horses were made to gallop on an 800m sand track at a speed of 12.8m/s.
• Three saliva samples and three blood samples were collected from each horse. These samples were collected when at rest, immediately after return from the track, and after 30 minutes of recovery.
• Concentrations of blood lactic acid (LA), and cortisol in saliva and plasma samples were measured and analyzed.

Findings

• There was a significant increase in the levels of blood LA, plasma and salivary cortisol post exercise.
• A significant correlation was observed between the amount of salivary cortisol concentration determined 30 minutes post exercise and the plasma cortisol level obtained immediately after the exercise as well as 30 minutes after the completion of exercise.

Conclusion & Implications

• The study concludes that the determination of cortisol concentration in saliva samples collected from racehorses 30 minutes post exercise can be effectively used in field conditions to estimate the work-load of racehorses.
• This finding has potential implications for managing the training and performance of racehorses, by providing a non-invasive, reliable indicator of stress and workout intensity.