Comparison of plasma biochemical parameters in Thoroughbred and Purebred Arabian horses during the same-intensity exercise.

This study compares the physiological impacts of moderate-intensity exercise on two different breeds of racing horses, Thoroughbreds and Purebred Arabians. The findings reveal Thoroughbreds demonstrated better adaptation to the exertion, indicated by differences in key plasma biochemical markers related to lipid metabolism.

Research Objective and Methodology

• The researchers set out to compare the blood parameters in Thoroughbreds and Purebred Arabian horses when subjected to the same intensity of exercise in similar conditions. The goal was to evaluate how different breeds respond to exertion.
• This study was executed on 20 stallions; half were Thoroughbreds aged 2-3 years, and the remaining half were Purebred Arabians aged 3-4 years.
• All the horses were put through an effort test that comprised a 1200 meter gallop at a speed typical of their daily training sessions.
• Jugular venous blood samples were obtained from each horse at rest, just after the gallop, and after a 30-minute rest.

Measurements and Findings

• In the collected blood samples, a varied range of parameters were inspected. These included hemoglobin concentration and plasma levels of glucose, triacylglycerols, glycerol, free fatty acids, total plasma proteins, and the activities of enzymes such as creatine kinase, lactate dehydrogenase, and aspartate aminotransferase.
• For Arabian horses, increases in levels of total plasma proteins, glycerol, free fatty acids and creatine kinase activity were notably higher post-exercise than those in Thoroughbreds.
• Even after a 30-minute rest, the post-exercise spike of specific parameters (total plasma proteins, aspartate aminotransferase, glycerol, free fatty acids) in Purebred Arabians remained higher than in Thoroughbreds.
• The only parameter where Arabian horses demonstrated lower values was in triacylglycerol plasma concentration measured 30 minutes post-exertion.

Study Conclusions

• The findings of this study suggest that Thoroughbred horses demonstrated better physiological adaptation to the effort test compared to Purebred Arabian horses.
• The most sensitive markers of breed differences in response to moderate-intensity exercise were parameters associated with lipid metabolism. These metabolic differences could be due to different genetic traits or adaptations developed over generations of selective breeding, but further research would be needed to confirm this.