Intense Leisure Exploitation Influences on Horses Hormonal Reaction—Preliminary Study

Abstract

Horses working with humans for recreational purposes are subjected to a variety of external factors that can have a negative impact on their well-being. There is an urgent need for unequivocal evidence from scientific studies to unify methods of welfare verification of working animals. The testosterone/cortisol ratio has recently been proposed as a marker of the propensity for social aggression as one of the stress reactions. In this study, we analyzed testosterone and cortisol blood concentration and ratio to evaluate the stress susceptibility of horses used for recreational purposes. The blood samples were collected from eleven (n = 11) standardbred horses (age 6–10; geldings–mares = 6:5) during the intense leisure exploitation and after the rest season. The cortisol concentration remained unchanged, whereas, despite the small study population, we observed higher testosterone levels during the horses’ intensive exploitation compared to the resting season (p > 0.09). Thus, the testosterone/cortisol ratio was increased during intensive exploitation. We conclude that recreational horseback riding is not an overly stressful activity for horses; however, it may lead to some behavioral abnormalities connected with high testosterone levels. However, more research is needed.

Exercise-related changes in the anabolic index (testosterone to cortisol ratio) and serum amyloid A concentration in endurance and racehorses at different fitness levels

“…Blood samples were collected before starting the exercise (1 h before feeding) and immediately after the end of the race training/max. 30 min after the end of the endurance effort, as a part of standard veterinary diagnostic procedures, which is in line with other studies ( 11 , 20 , 23 , 24 ). Thus, no approval of the Local Commission for Ethics in Animal Experiments was required, according to the Polish legal regulations and the European directive EU/2010/6.…”

“…30 min after the end of the endurance effort as a part of standard veterinary diagnostic procedures, so the longer/shorter duration of sampling was impossible. However, it is in line with sampling protocols presented in previously published studies ( 11 , 20 , 23 , 24 ).…”

“…Given the interplay of C and T in maintaining anabolic-catabolic balance and their highly sensitive response to acute and chronic exercise, testosterone-to-cortisol ratio (T/C) is a helpful parameter for indication of exercise intensity loaded on the individual and the consequences of this stress in the context of behavioral changes, overreaching, overtraining, strength gain, recovery, and adaptation to the following effort ( 9 – 11 ). The T/C, an absolute number also referred to as the anabolic index, has been shown to drop by more than 30% in human athletes with symptoms of overtraining and poor performance.…”

“…However, in equine athletes, there is a lack of studies concerning the changes and usefulness of the T/C ratio. There is only one preliminary study confirming that the anabolic index does not change in leisure horses after training season ( 11 ).…”