Speed associated with plasma pH, oxygen content, total protein and urea in an 80 km race.

The research explores the impact of certain blood variables on the endurance performance of horses during an 80 km race. The study investigates whether changes in blood, measured through specific variables such as plasma pH, oxygen content, total protein and urea, can quantitatively relate to the speed. The findings reveal that conditioning horses with fat-fortified and protein-restricted diets may improve their performance, thereby avoiding grain-associated disorders.

Background and Study Design

• This research aimed to examine the hypothesis that endurance performance in horses might have a quantitative relationship with variations in their blood.
• A set of selected blood variables were measured to establish their reference ranges and associations with speed during an 80 km horse race.
• The study used a 2 x 2 factorial design that involved 46 horses and tested a potassium-free electrolyte mix and a vitamin supplement.
• Blood samples were collected at multiple points throughout the race, as well as before the race and 20 mins after completion, to assay several blood variables such as plasma pH, pO2, cortisol, total protein, urea and more.

Data Analysis

• Statistical analysis was conducted on data from the 34 horses that completed the race.
• Findings revealed that reference ranges for resting and running horses were wide and overlapping, which complicated the evaluation of individual horses.
• Highest repeatability was found in speed correlations with variables that indicated blood oxygen transport, acidity and electrolytes, and total protein.
• Stepwise regressions also included plasma urea concentration.

Conclusion and Implications

• The study found a connection between speed and lower plasma acidity and urea.
• This suggests potential for fat adaptation and protein restriction in endurance horses, consistent with previous findings in Arabian horses performing repeated sprints.
• The research concludes that conditioning horses with fat-fortified and protein-restricted diets may enhance their performance and potentially avoid grain-related disorders.