Improvement in Semen Conservation of the Indigenous Czech Endangered Old Kladruber Horse: Special Focus on the Type of Extender and Packaging System.

This research article seeks to identify the most effective methods for preserving the semen of Old Kladruber horses, a critically endangered breed, by examining the impact of two different freezing storage methods and two different packing materials. The findings reveal that a combination of a specific freezing storage method (Gent) and a specific packing material (0.5mL straws) best maintains the quality of the spermatozoa.

Methods

• The study begins by collecting semen from six Old Kladruber stallions, with three collections from each.
• This semen is then diluted using either a Gent extender or a Lactose-EDTA (Lact) extender.
• Two aliquots (separate portions) of diluted semen from each collection are prepared. These are then stored in either 5ml aluminium tubes or 0.5ml plastic straws.
• Once the semen is thawed (defrosted), it’s analysed at 15-minute intervals for one hour to measure its motility (capacity to move), plasma membrane (PM) integrity (health), and apoptotic changes (cell death).

Findings

• The Gent extender was found to be more beneficial as it resulted in higher motility, better PM integrity, and fewer apoptotic changes in the sperm cells compared to the Lact extender.
• In terms of packaging, the semen stored in 5mL aluminium tubes displayed superior PM integrity and progressive motility when used with the Gent extender.
• However, the 0.5mL plastic straws scored better in terms of kinematic parameters (attributes related to motion), percentage of fast subpopulation of sperm cells, and apoptotic status when used with Gent.

Conclusion

• This research suggests that the combination of using a Gent extender and 0.5ml straws as packaging best maintains the quality of Old Kladruber horse sperm.
• The findings highlight the importance and need for suitable conservation methods to prevent the extinction of endangered species like the Old Kladruber horses.