Raffinose and hypotaurine improve the post-thawed Merino ram sperm parameters

Area of Science:

• Animal Science
• Reproductive Biology
• Cryobiology

Background:

• Cryopreservation of ram semen is crucial for artificial insemination and genetic preservation.
• Freeze-thawing process can significantly damage sperm parameters, affecting fertility.
• Antioxidants are investigated to mitigate cryodamage in spermatozoa.

Purpose of the Study:

• To evaluate the efficacy of raffinose and hypotaurine in protecting Merino ram sperm during cryopreservation.
• To assess the impact of these antioxidants on sperm motility, viability, mitochondrial activity, acrosome integrity, and DNA integrity post-thaw.

Main Methods:

• Semen from Merino rams was diluted in Tris-based extenders with raffinose, hypotaurine, or a combination (H+R).
• Samples were frozen, stored in liquid nitrogen, and thawed individually for analysis.
• Sperm parameters including motility (subjective and CASA), viability, mitochondrial activity, acrosome integrity, DNA damage (Comet assay, TUNEL assay) were evaluated.

Main Results:

• Raffinose supplementation increased subjective and CASA motility compared to controls (P<0.05).
• Both raffinose and hypotaurine improved sperm viability, mitochondrial activity, and acrosome integrity (P<0.05).
• Raffinose and hypotaurine significantly reduced DNA damage, as evidenced by lower percentages of DNA fragmentation in Comet and TUNEL assays (P<0.05).

Conclusions:

• Raffinose and hypotaurine supplementation effectively protect Merino ram sperm parameters against cryopreservation-induced injury.
• These antioxidants enhance post-thaw sperm quality, offering potential benefits for artificial insemination programs.
• The study demonstrates the protective role of raffinose and hypotaurine in preserving sperm integrity during freezing and thawing.