Relationship between maximum eye temperature and plasma cortisol concentration in racehorses during intensive training.

The research article is about a study exploring the link between maximum eye temperature and plasma cortisol levels in racehorses during intense training. Using infrared thermography, the researchers found that both factors could be potential indicators of stress in these animals.

Study Objective

• The primary objective of this study was to ascertain if maximum eye temperature, as measured by infrared thermography (IRT), could be used as an effective indicator of stress levels in racehorses. This was contrasted with the more conventional method of gauging stress through plasma cortisol concentrations.

Study Design and Participants

• The study involved thirty Thoroughbred and Arabian racehorses currently engaged in a standard training program for racing competitions.
• The researchers conducted tests at three different stages: before training (BT), within 5 minutes after the session (5AT), and within 120 minutes post-training (120AT).
• The study repeated these observations three times with a monthly interval between each session.

Measurements and Data Collection

• The maximum eye temperature of the horses was recorded using infrared thermography, a non-invasive imaging technique that captures the infrared heat emissions from the eye.
• Blood samples were collected at each measurement point to establish the plasma cortisol concentration, a hormone typically associated with stress.

Key Findings

• Both the maximum eye temperature and plasma cortisol levels increased directly after the training session (5AT) in comparison to before the training (BT).
• 120 minutes after the training (120AT), the maximum eye temperature still remained elevated, while plasma cortisol levels had decreased.
• The correlation between the two measurements was weak (r=0.220), but still significant.

Implications and Conclusion

• The results of this research suggest that the use of IRT to measure maximum eye temperature could be a significant method to monitor the response of horses to stress.
• This use of non-invasive IRT to monitor stress could potentially improve horse management practices and overall animal welfare by providing an easy and less stressful method of measuring stress levels in horses during intensive training.