Whole blood selenium concentrations in endurance horses.

The research article investigates the concentration of Selenium (Se), a known antioxidant catalyst, in the blood of endurance horses from California due to potential Se deficency from the region’s forage. The study found a low rate of Se deficiency, no concrete link between high Se concentration and improved performance, but noted increased Se concentration in horses after exercise.

Importance of Selenium in Endurance Horses

• Exercise can lead to increased production of reactive oxygen species which, without a sufficient supply of antioxidants, can cause an imbalance favoring pro-oxidation.
• Among antioxidants, Selenium (Se) plays a crucial role as it forms part of the glutathione peroxidase enzymes.
• Endurance horses prone to oxidative stress due to prolonged aerobic exercise could have their performance impacted by their Se status.

Selenium Supply in the Diet

• Soils and forages, which contribute to the diet of horses, vary widely in their Se concentration.
• A Se-deficient diet can lead to sub-clinical or clinical deficiency in horses, which may impact overall health and performance.
• The study focuses on a group of endurance horses from California, a region which tends to produce Se-deficient forages.

Findings of the Study

• The rate of Se deficiency in the group of horses studied was relatively low, with only one horse slightly below the reference range, indicating that the Se intake via their diet was adequate for the most part.
• There was no defined association between higher blood Se concentrations and improved performance in terms of ride time, indicating that having higher-than-required Se in the blood doesn’t necessarily improve performance.
• No significant difference in Se concentration was observed between horses that completed the ride and those that were disqualified, possibly illustrating that Se levels do not directly affect the ability to complete a ride.
• Horses that received oral Se supplementation had significantly higher blood Se concentrations, indicating that oral supplements can effectively elevate Se levels.

Post-Exercise Selenium Concentration Changes

• An increase in blood Se concentration was observed following exercise, but the phenomenon’s implications need to be further studied to understand its effects on horse health and endurance.