Relationship between serum cortisol levels and some physiological parameters following reining training session in horse.

The changes of cortisol, red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), heart rate (HR), respiratory rate (RR) and rectal temperature (RT) were evaluated after a reining training session in eight Quarter Horses. All parameters were measured before exercise (T0), immediately after exercise (T1), 1 h after exercise (T2), 2 h after exercise (T3) and 24 h after exercise (T4). One-way analysis of variance (ANOVA) for repeated measures, followed Bonferroni's post hoc test, showed a significant effect of the reining training session (P < 0.0001) on cortisol, RBC, Hb, Hct, HR, RR and RT. Simple linear regression analysis showed the positive correlation (P < 0.05) between cortisol changes and variations of studied parameters in T1, T3 and T4. Exercise-induced cortisol concentrations reflect the physiological response of reining training, suggesting that the changes observed are useful to assess the performance in reining horses and their reining training adaptability.
(© 2015 Japanese Society of Animal Science.)