Relationship of intratesticular testosterone content of stallions to age, spermatogenesis, Sertoli cell distribution and germ cell-Sertoli cell ratios.

The research analyses the correlation between intra-testicular testosterone levels in stallions and various factors like age, spermatogenesis, Sertoli cell distribution and germ cell-Sertoli cell ratios. The conclusion suggests that intra-testicular testosterone increases with age, it positively influences sperm production and can account for the variance in sperm production among stallions in a single breeding season.

Objective

In order to understand the relationship between the testosterone content within the testes of stallions and their age, spermatogenesis, Sertoli cell distribution, and germ cell-Sertoli cell ratios, 47 1-20 year-old stallions were studied throughout a natural breeding season.

Finding and Conclusions

• The total testosterone in the testes and the ratio of testosterone per gram of testes tend to increase as the stallions advance in age. Furthermore, larger testis size is associated with higher total testicular testosterone.
• Greater levels of testosterone per paired testes relate to fewer Sertoli cells for any given quantity of seminiferous tubule length or basement membrane area. It’s also linked to a higher share of germ cells per Sertoli cell.
• While testosterone levels per gram of testes and per pair of testes did not have a substantial link to Sertoli cell count, or to the production and yield of spermatids per spermatogonium, the testosterone levels per pair of testes had a positive correlation with sperm production.

After the research, it was concluded that intratesticular testosterone in stallions elevates as the stallion ages, it positively correlates to quantitative rates of sperm production, and can explain some disparities in sperm production among individual stallions within a single breeding season.

Significance of the research

This research is significant because it contributes to the understanding of equine reproductive physiology, specifically how testosterone levels within a stallion’s testes affects various factors like age, sperm production, and Sertoli cell distribution. The research findings could enhance the management of stallion breeding programs by pinpointing the key factors that contribute to successful sperm production.