Factors influencing boar sperm cryosurvival

Area of Science:

• Animal Science
• Reproductive Biology
• Cryobiology

Background:

• Optimal cryopreservation of boar semen is crucial for the commercial success of artificial insemination (AI).
• Variability in post-thaw sperm survival among ejaculates poses a challenge to consistent AI outcomes.
• Identifying factors influencing this variability is essential for improving cryopreservation protocols.

Purpose of the Study:

• To investigate factors affecting post-thaw sperm survival in cryopreserved boar semen.
• To determine the relative importance of boar, semen collection, and pre-freezing traits on sperm cryosurvival.
• To assess the consistency of sperm cryosurvival within individual boars over time.

Main Methods:

• Cryopreservation of boar semen using standard procedures and computer-controlled freezing.
• Assessment of post-thaw sperm motility via computer-assisted semen analysis (CASA).
• Evaluation of sperm viability using flow cytometry with triple-fluorescent staining at 30 and 150 minutes post-thaw.

Main Results:

• Boar identity accounted for over 70% of the total variance in post-thaw sperm quality.
• Pre-freezing semen traits and sperm quality explained 23.2% and 10.9% of the variation in post-thaw motility and viability, respectively.
• Boar and semen collection/transport variables were not predictive of cryosurvival, but individual boars showed consistent cryosurvival over time.

Conclusions:

• Boar is the most significant factor influencing sperm cryosurvival variability in frozen-thawed semen.
• Individual boar characteristics are more critical than collection/transport variables for successful cryopreservation.
• Consistent cryosurvival within boars suggests potential for selecting superior animals for semen preservation.