The Influence of Blood, Seminal Plasma Testosterone, Growth Hormone and Cortisol Levels on the Sperm Quality in Merino Rams

The research was conducted on 10 Merino rams to determine the effect of testosterone, growth hormone and cortisol levels on the sperm quality. A significant relationship was detected between blood and seminal plasma levels of testosterone (P ˂ 0.01). No GH on a measurable level was detected in the seminal plasma, and it was determined that plasma GH levels, just as testosterone levels began to increase with the approach of the reproductive season, and peaked at the start of the season. Plasma and seminal plasma cortisol levels, on the other hand, while increasing before the season, decreased significantly at the start of the season, and a remarkable correlation between plasma and seminal plasma levels was ascertained (P ˂ 0.01). An important negative relation which was observed between plasma GH levels and seminal plasma cortisol levels in Merino rams. It was found out that the hormones that were examined did not have a significant influence on sperm qualities, but there was an important negative relation only between the plasma GH levels and sperm volumes in the Merino (P ˂ 0.01). In conclusion, it may be stated that in rams, especially plasma testosterone and cortisol levels determine the plasma levels; both plasma and seminal plasma testosterone levels increase to a significant degree in the reproductive season.