Seasonal changes in FSH and testosterone in Shami bucks in Iraq

The levels of FSH and testosterone were measured in sera of ten Shami bucks over a period of twelve months. Result showed that concentration of Follicular stimulating hormone (FSH) and Testosterone were increased significantly (P 0.05) during autumn and summer as compared to other seasons of the year. On monthly basis significantly (P 0.05) higher concentration was observed during August, September and November for Testosterone. Furthermore, FSH shows highest concentration during October. These results indicate that the environment changes associated with seasonal changes affects the activity of the hypothalamic-testicular axis leading to a decrease or increase these hormones.