Optimization of the Protocol for Cryopreservation of Arabian Stallion Spermatozoa: Effects of Centrifugation, Semen Extenders and Cryoprotectants.

This research looks into how to best preserve Arabian stallion sperm using various centrifugation techniques, semen extenders, and cryoprotectants. Their findings reveal that specific methods and substances can significantly improve sperm function and fertility after freezing and thawing.

Experiment Details

• The researchers collected semen samples from four adult Arabian stallions once a week over a ten-week period. Some samples were processed without centrifugation (NC) while others were centrifuged with the gel-free fraction.
• Six variations of centrifugation were under consideration: protocols based on changing spinning speed (600, 900, 1200 x g) and duration (10 or 15 minutes). This was known as Experiment 1.
• They also compared the performance of two semen extenders, the INRA-82 and the modified Kenney’s extenders, on sperm preservation quality – referred to as Experiment 2.
• In the final experiment (Experiment 3), they tested three cryoprotectants, namely 5% glycerol, 5% dimethylformamide (DMF) and a mix of 2.5% glycerol with 2.5% DMF.
• After each freezing and thawing cycle, the researchers assessed the motility, viability, plasma membrane integrity, acrosome status and viability index of the sperm.

Analyzing the Results

• Results showed centrifuging semen at 600 x g for 15 minutes before cryopreservation had the best outcome. According to these parameters, sperm demonstrated increased motility, viability, plasma membrane integrity, and the percentage of spermatozoa with intact acrosome surpassed other centrifugal protocols.
• When comparing semen extenders, the INRA-82 mix was found to be more effective than modified Kenney’s. Sperm quality after the freeze-thaw cycle was better in samples preserved with INRA-82.
• From the three cryoprotectants tested, supplementing semen diluent INRA-82 with 5% DMF led to a robust quality of frozen/thawed Arabian stallion spermatozoa than 5% glycerol.

Conclusions

• The study concludes that optimizing factors like centrifugation, types of semen extenders, and cryoprotectants play an indispensable role in processing Arabian Stallion spermatozoa for cryopreservation.
• The findings indicate that a centrifugation process of 600 x g for 15 minutes, the use of INRA-82 semen extender, and a 5% DMF cryoprotectant provide the best results for the cryopreservation of Arabian stallion sperm.