Biomarkers of Stress and Inflammation in Assessing the Quality of Welfare of Conditioned Vaquejada Horses

In recent decades, the intensity of training and equestrian competitions has significantly increased, thus the assessment of the well-being of the equine athlete has become essential in all equestrian modalities. The aim of this study was to ascertain whether equine athletes submitted to a vaquejada simulation test (VqST), comprised of three races, presented changes in blood biomarkers related to stress and health status. Fourteen healthy Quarter Horses, used as pull horses in this equestrian modality, were evaluated. Ten animals were submitted to the VqST and the remaining four were used as a control group. Blood samples were collected pre-test (during fast), immediately after, and at 1, 4 and 24 hours of recovery. The assessed blood biomarkers included cortisol, interleukin (IL)-6, IL-1β, iron, urea, creatinine, and gamma-glutamyl transferase (GGT) concentrations and results were analyzed using One Way ANOVA (time) with the SigmaStat 13.0 software. No differences between sample times were detected in both groups (p > 0.05) and no differences were found between groups (p > 0.05). The results suggest that all horses were well conditioned for the level of effort imposed by the three vaquejada races. The adaptation to physical exercise may enable the regulation of the acute response to stress in the tissues involved in the exercises, with no differences being observed in stress and health biomarkers, such as IL-6, IL-1β and cortisol. In conclusion, well-conditioned vaquejada horses exhibit a balanced regulation of biological processes, which contributes an increased athletic longevity and better quality of athletic life.