Effects of Cool and Hot Humid Environmental Conditions on Neuroendocrine Responses of Horses to Treadmill Exercise

Circulating β-Endorphin, Adrenocorticotropin, and Cortisol Concentrations of Horses Before and After Competitive Show Jumping with Different Fence Heights

“…Previous data reported that in the horse, treadmill exercises at submaximal levels produce significantly increased concentrations of b-endorphin, but a differential response between fit and unfit horses has been reported [22]. Changes in plasma b-endorphin concentrations of horses were also recorded after a strenuous competition (3-day event) and after exercise tests on treadmill, before and after acclimation to thermal stress [45].…”

“…A lack of correlation in the evolution of b-endorphin and cortisol concentrations has been reported in different stressful conditions with a high emotional content [39,45,48]. The discriminating sensitivity of the HPA axis to emotional values of the adverse environmental stimuli justifies the use of HPA hormone levels in the monitoring of animal welfare [10,11].…”

“…The cortisol levels of horses at rest before and 48 hours after show jumping competition [18] resulted in significant differences with respect to competition stress; after exercise, the cortisol response appeared to be correlated with the duration of exercise, but not with plasma ACTH [28], and with the state of individual fitness [2,17], as well as with b-endorphin concentrations during emotional conditions [39,45,48]. In this study, the postexercise cortisol response was found to be dependent on fence height, with significant differences 5 minutes after exercise, independent of difficulty score, and different from what has been generally reported [1,6], higher than pre-exercise levels still 30 minutes post exercise, with significant differences only in horses that competed in the most difficult category (group III).…”

Glicemia e concentrações séricas de insulina, triglicérides e cortisol em equinos da raça Mangalarga Marchador após exercício físico

“…Segundo Hyyppä (2005), sua principal função é prover a biodisponibilidade dos precursores energéticos necessários para manter os esforços musculares através de diversas vias de ação, dentre as quais degradação de proteínas teciduais para liberação de aminoácidos usados na gliconeogênese hepática, mobilização de ácidos graxos livres do tecido adiposo e redução da taxa de utilização celular de glicose. No repouso, Marc et al (2000) citaram intervalo de valores entre 1,47 e 6,73mg/dL e Williams et al (2002) descreveram valores entre 4,5 e 7,5mg/dL. Trabalho mais recente de Dugat et al (2010) cita valores oscilando entre 2,9 e 6,6mg/dL.…”

Influence of a calmative on selected blood parameters in horses under stressful conditions

“…Stressors can include environmental changes, transport, exposure to novelty, weaning, fear due to restraint, contacts with people and training, but also injury or disease. Stress not only directly affects the well-being of the horse and its performance, but more importantly, its health condition, too (Art and Lekeux, 2005;Christensen et al, 2005;Ott, 2005;Stull et al, 2004;Shanahan, 2003;Williams et al, 2002;Grandin, 1997;Smith et al,1996).…”