Effect of ascorbic acid orally administration on the thyroid hormones (T3 and T4) before and after physical activity Arab-race horses

The aim of this study was to investigate the effect of orally administration of ascorbic acid on the levels of thyroid hormones (T3 and T4) in arabic horses. Forty arabic horses (average age 4-9 years and average body weight 450- 550 kg) clinically healthy were used. Animals were divided randomly in two groups of control and treatment. Then treatment group was given orally ascorbic acid (20gram) for one month daily. After this time, blood samples collected through jugular vein puncture at rest and immediately after galloping in 2160 meters. Results showed that T3 and T4 significantly increased (p<0.05) and ascorbic acid significantly decreased (p<0.05) in control and treatment groups after exercise compared with before galloping. In conclusion, we can suggest that the administration of ascorbic acid does not effect on the levels of thyroid hormones (T3 and T4) in arabic horses