Testosterone serum profile, semen characteristics and testicular biometry of Mangalarga Marchador stallions in a tropical environment.

The research article studies the daily testosterone secretion profile, semen characteristics and testicular measurements of Mangalarga Marchador stallions over the course of a year in a tropical environment. It concludes that the reproductive aspects of these stallions did not show a clear seasonal variation.

Testosterone Secretion

• The study conducted blood tests in the middle of each season to assess testosterone secretion patterns.
• Testosterone concentrations were found to be higher at the early afternoon, however, no clear circadian secretion pattern was observed.
• The study also noted that mean testosterone concentrations did not substantially differ between seasons.
• The testosterone secretion pattern during the day varied with the afternoon of winter season observing higher concentrations.

Semen Characteristics

• Ejaculate volume was observed to be higher during the summer season.
• However, a decrease in sperm motility was noted in the summer and spring seasons.
• The total number of sperm in the ejaculate, their morphology and testicular measurements were constant throughout the year without discernable differences between seasons.

Conclusion

• The study concludes that the reproductive processes of Mangalarga Marchador stallions in tropical climates do not demonstrate clear seasonal variations.
• Despite some minor cyclic variations in testosterone levels and semen characteristics, the study findings suggest that the autumn and winter months do not impede the stallions’ reproductive capabilities.