Serum levels of testosterone and oestrogens in normal and infertile stallions.

This research investigates the levels of testosterone and oestrogens in stallions’ blood serum to determine whether there is a correlation between these hormone levels and fertility. The study found significant differences between fertile and infertile horses, suggesting that these hormone levels could be a reliable indicator of stallions’ reproductive health.

Objective of the Research

• The research aimed to examine whether the levels of testosterone and oestrogens in the blood serum could be linked with fertility in male horses.

The Study and Findings

• Researchers compared the serum concentrations of testosterone and oestrogens in different groups of stallions – these groups included geldings (castrated horses), age-normal stallions, and infertile (azoospermic) stallions.
• The study found substantial differences in hormone levels among these groups. From 16 months onwards, stallions typically attained normal levels of testosterone and total oestrogens.
• Gelded and immature horses (less than 15 months old) exhibited lower levels of testosterone and total oestrogens compared to mature and infertile stallions.
• Infertile stallions, though, displayed a lower level of these hormones compared to normal, mature stallions, with one exception in which the total oestrogen was considerably higher.
• The results attained from the 6-15 months old colts and stallions aged above 4 years were consolidated to form critical ellipses for testosterone and total oestrogens.

Conclusion of the Research

• The research concluded that blood serum levels of testosterone and total oestrogens can potentially serve as an effective measure, indicating the endocrine system’s function in stallions. This evaluation of hormone levels might thereby act as a useful tool in the assessment of male horses’ reproductive health.