Antioxidant Status in Elite Three-Day Event Horses during Competition

Abstract

The objective of this study was to determine if competition intensity would have an effect on antioxidant status in horses before and during a three-day event. Body weight, body condition score, and blood was sampled from CCI2* (n = 19) and CCI3* (n = 23) horses before the start of dressage, 20 to 30 min following cross-country, and 18–24 h after cross-county. Data were analyzed using a PROC MIXED in SAS. There were no differences between CCI2* and CCI3* horses during competition for plasma cortisol, lactate, α-tocopherol, retinol, or erythrocyte glutathione peroxidase. After cross-country, CCI3* horses had higher serum creatine kinase (P = 0.003) and aspartate aminotransferase (P < 0.0001) than the CCI2* horses. Plasma β-carotene was higher in the CCI2* horses compared to the CCI3* horses (P = 0.0001). Total erythrocyte glutathione was also higher in the CCI2* horses versus CCI3* horses (P < 0.0001). These results are the first report of antioxidant status of horses competing in this level of a three-day event. The changes in antioxidant and muscle enzymes observed between divisions are likely due to the increased anaerobic and musculoskeletal demand on the upper level horses and the fitness required to compete at that level.

Blood‐based assessment of oxidative stress, inflammation, endocrine and metabolic adaptations in eventing horses accounting for plasma volume shift after exercise

“…The small increase in SOD levels shortly after the end of exercise indicates that ROS production occurs during exercise, leading to the activation of antioxidative defence systems. However, this does not indicate that there is a discrepancy between ROS production and antioxidant systems, which could constitute pathological oxidative stress (Williams & Burk, 2012). But as ROS are difficult to measure due to their short half‐lives, metabolic products and cofactors must be used for measurement (Bollinger et al., 2023).…”

“…Metabolic stress is caused by the increased energy requirements of physical exercise. Cross‐country exercise places aerobic and, as difficulty increases, increasingly anaerobic metabolic demands on the equine body (Amory et al., 1993; Muñoz et al., 1999; Williams & Burk, 2012). Anaerobic energy can be supplied through anaerobic glycolysis from glucose and through the creatine–phosphate–ATP pathway (McGowan et al., 2002).…”

“…To reduce the harmful effects of ROS, antioxidant defence systems play a crucial role, consisting of enzymatic components like superoxide‐dismutase (SOD) and non‐enzymatic components like tocopherols (Siqueira et al., 2014). Williams and Burk (2012) found that markers of antioxidant status were upregulated in eventing horses after difficult exercise, which they attribute to increased scavenging of ROS.…”

Muscle damage and behavioral consequences from prolonged handling of albatross chicks for transmitter attachment

“…Differences in response times of these 2 enzymes support our model results where CK and AST were selected to best explain pre‐ and post‐fledging behavior, respectively, given the variables that we sampled. Capture and handling events also elevate the blood levels of the stress hormone corticosterone, which promotes fledging behavior in chicks and positively correlated with CK level (Heath , Lin et al , Sprague and Breuner , Williams and Burk , but Navarro et al ). Short‐tailed albatross chicks with transmitters might also have elevated levels of corticosterone, but corticosterone would need to be sampled to determine the direct relationship of this stress hormone and muscle enzyme levels under these conditions.…”

Аcid resistance and population structure of erythrocytes in trotter horses during and after exercise

“…Knowledge of the functional and metabolic processes occurring in a particular sport discipline is extremely important for understanding what metabolic paths are involved, and which physiological processes are induced during various physical activities (Bergero et al, 2005). It has been proved that horses undergo changes between the balance of oxidant and antioxidant systems, depending on the exercise type, its intensity and duration, training condition, environmental conditions, and presence of diseases (Kirschvink et al, 2006;Williams and Bur, 2012).…”