Quantitative buffy coat analysis related to adrenocortical function in horses during a three-day event competition.

This research studied the effect of stress on horses during a three-day event competition. The stress was measured using plasma cortisol levels and white blood cell changes were also evaluated. Initial findings showed increased values right after the event, and although most values returned to normal 180 minutes post-event, some parameters remained elevated. A strong correlation was found between increased cortisol levels and white blood cell changes, thus suggesting that the latter could be a reliable estimation of the stress exerted on the horses during exercise.

Research Methodology:

• The researchers conducted the study on seven healthy horses participating in a three-day event competition. The aim was to understand possible stress induced in the animals during the cross-country event.
• Blood samples from the horses were taken under resting conditions, and then 2 minutes and 180 minutes after completing the cross-country event. Hematological parameters, as well as plasma cortisol, protein, and lactate levels, were studied from these samples.
• The researchers used Quantitative Buffy Coat (QBC) analysis for evaluating hematological parameters. QBC analysis can be conducted in field conditions making it a convenient method for such a study.

Research Findings:

• The researchers found a significant increase in cortisol, protein, lactate, and leucocytic levels just after the event. The only parameter that did not increase was the granulocytes (Gr) to lymphocytes-monocytes (LM) ratio.
• 180 minutes after the event, all the mentioned parameters returned to resting levels except for the White Blood Cells (WBC), Gr and Gr/LM ratio, which appeared to be significantly higher than their resting values.
• The researchers found a high correlation between the increase in plasma cortisol levels 2 minutes post-exercise and the increase in Gr/LM ratio 180 minutes post-exercise. The correlation was 0.82, which is considered strong.

Conclusions and Implications:

• The findings led the researchers to conclude that the Gr/LM ratio measured 180 minutes post-exercise using QBC analysis provides a reliable estimation of the plasma cortisol levels measured 2 minutes after exercise.
• This new technique could be used in a field environment to measure exercise-induced stress in horses. It helps provide a useful tool in understanding and managing the health and wellbeing of horses, especially in physically demanding activities.