The effect of two levels of hemospermia on stallion fertility.

This study investigates the effect of blood in stallion ejaculate, known as hemospermia, on fertility, finding that a higher level of hemospermia significantly reduces fertility while a lower level does not affect it.

Background and Objectives

• This research was carried out to understand the effect of hemospermia on stallion fertility. Hemospermia, or the presence of blood in an ejaculate, happens consistently or intermittently and can potentially reduce fertility.
• The level of blood in the ejaculate that leads to subfertility was unknown, prompting the necessity for this study. The researchers looked into two distinct levels of hemospermia – 50% and 5%, to assess their effect on fertility.

Methodology

• The research involved 24 reproductively normal mares that were inseminated over three consecutive estrous cycles with fresh extended semen.
• The semen used was either not contaminated by blood (the control group), contaminated by 5% blood, or contaminated by 50% blood. Hence, three groups of mares were inseminated under various conditions.

Results

• The fertility rate remained the same, at 75% per cycle (or 18 out of 24 mares became pregnant) when the mares were inseminated with either blood-free semen or semen with 5% blood. This suggests that a lower level of hemospermia does not impact fertility.
• However, when the semen contained 50% blood, the fertility rate dropped to 0%; none of the 24 mares inseminated with this semen became pregnant. It shows that a higher level of hemospermia drastically reduces fertility.

Conclusion

• The study concludes that it’s the quantity of blood present in an ejaculate, not just its mere presence, that significantly impacts fertility in stallions.
• Thus, it’s vital to manage conditions leading to higher levels of hemospermia in stallions to maintain their reproductive health and ensure the sustainability of the species.