The effect of castration on cortisol changes and blood glucose in horses

Abstract

Behavioral changes in stallion will happen after castration. Usually, behavioral changes are followed by hormonal changes. It seems that removing the testicles has an effect on other endocrine glands including the thyroid gland, hypothalamus, and adrenal glands. Adrenal hormones have an effect on behavior. In this study, cortisol concentration was measured after a surgery in order to determine the relationship between horse’s castration, adrenal gland excretion, and level of stress. Twelve horses were selected for surgical castration. Scrotal incision and closed approach technique were performed for both testicles. Blood was taken before surgery, 10 and 30 days after surgery (castration). Blood glucose was measured by glucose oxidase and then serum and plasma hormones cortisol were measured. Finally, Paired sample t test was performed for statistical analysis using SPSS 16 software (SPSS Inc., Chicago, IL, USA). No significant changes in cortisol were found between the horses before, 10 and 30 days after the surgery (p > 0.05). Significant changes were found only between the samples that were taken before surgery and 30 days after surgery in blood glucose concentration (p < 0.05). There were no significant hormonal changes after castration. Castration does not seem to affect cortisol secretion; however, its effect on blood glucose concentration was evident.