[The influence of centrifugation on quality and freezability of stallion semen].

The research study investigates the impact of different centrifugation methods on the loss of sperm and the quality of frozen-thawed stallion semen.

Objectives and Methods

• The main aim was to understand how varying centrifugation methods affected sperm loss and the quality of frozen-thawed semen from stallions.
• The researchers used semen from 8 Warmblood stallions from the National Stud Farm in Avenches.
• Three ejaculates were collected from each stallion and the seminal plasma was removed through three different centrifugation regimes.
• In Method I (control method), centrifugation was performed at a speed of 600 x g for 10 minutes. Method II involved centrifugation at 1000 x g for 2 minutes, and Method III consisted of centrifugation at 2000 x g for 2 minutes.
• Post-centrifugation, 90% of the supernatant was removed and sperm loss was determined. The quality of the frozen-thawed semen was then assessed based on various parameters including motility, viability, functional membrane integrity, and acrosome status.

Key Findings

• The findings revealed significant differences in sperm loss among the different centrifugation methods.
• The sperm loss was 1.9% in Method I, 8.7% in Method II, and 3.7% in Method III.
• The quality of frozen-thawed semen, specifically its functional membrane integrity (indicated by the HOS test), also varied with the centrifugation procedure. Method III resulted in the lowest HOS score (52.1%) compared to Method I (55.5%) and Method II (55.3%).
• Assessment of the acrosome status showed that more than 70% of sperm cells were capacitated and 25% were both capacitated and acrosome-reacted.
• Thus, the study concluded that the centrifugation method significantly impacts sperm loss and quality of frozen-thawed semen.

Necessary Precautions

• Basing on the results, the study recommends that stallion semen should be centrifuged at 600 x g for 10 minutes before freezing. This procedure results in minimal sperm loss and high-quality frozen-thawed semen.