The Effects of Melatonin Application on Some Haematological Parameters and Thyroid Hormones and Testosterone in Male Goats' Non-Breeding Season

Abstract

In the present study, the effects of melatonin application on some haematological parameters, testosterone and thyroid hormones in male goat in out of breeding season were investigated. In this study 16 Coloured Mohair male goats were used. At the beginning of the study the animals were randomly divided into two equal groups as control and test groups. Melatonin (Regulin, Hoechst) was implanted in the test group. Thirty and 70 days after melatonin implantation, blood samples were obtained from both control and melatonin groups for determination of erythrocyte and leukocyte counts, haemoglobin concentration, haematocrit level, plasma testosterone, T3 and T 4 concentrations. T3 and T4 levels were lower both 30 and 70 days after melatonin implantation in the test group compared to the values obtained from the control group. However, important decreases (P<0.05) were seen only in T3 concentration obtained from the melatonin group on day 70 of the experiment. Testosterone values increased in the melatonin-implanted group for 30 and 70 days after implantation, but results were not significant. Accordingly, it is believed that the effects of melatonin implantation on certain haematological parameters, testosterone and thyroid hormone levels in male goats in the non-breeding season, should be taken into consideration.