Motility and ATP content of extended equine spermatozoa in different storage conditions.

This research investigated the effects of multiple conditions on horse sperm motility and ATP content, finding that certain storage environments significantly improve sperm survival.

Research Overview

• The research was conducted by collecting sperm samples from 10 stallions. The sperm samples were placed in different mediums under various conditions to test their survival rate.
• Both raw (unprocessed) and washed (processed to remove additional seminal fluid) spermatozoa were used in this experiment.
• The scientists utilized an open-ended artificial vagina for the collection of sperm, which is a common method used for animal breeding research.

Conditions and Their Impact on Sperm Survival

• When left unattended in the original seminal fluid, the sperm did not live beyond 12 hours under any circumstances.
• However, survival greatly improved when different media were used. Kenney’s medium, both alone and with additional substances (10 mM-theophylline and 10 mM-Hepes, pH 7.2), proved to be the most advantageous for the longevity of the spermatozoa.
• The slow cooling of the media to 5-7°C as well as the addition of a 5% CO2 atmosphere or storage in a closed plastic bag with no air-space also improved survival.
• With these adjustments, some sperm were able to survive for 4-5 days.

Pregnancy Rates

• The researchers also scratched the surface of the practical application of these findings by examining pregnancy rates.
• Mares (female horses) were inseminated with the extended and cooled spermatozoa that had been stored for 24 hours in the improved conditions.
• 16 days after oestrus (female reproductive cycle), the mares showed a promising pregnancy rate: 82% for sperm stored in Kenney’s medium and 70% for the medium supplemented with theophylline and Hepes.
• This highlighted the potential real-world applicability of these findings for enhancing the success rate of artificial insemination procedures in horses.