Effects of Slow and Rapid Thawing on Bull Semen Quality: An Evaluation via Thermal Resistance Test

This study aimed to comparatively evaluate the impact of two different thawing protocols—slow thawing at 37°C for 30 seconds and rapid thawing at 70°C for 6 seconds—on bull semen quality, with a particular focus on the thermal resistance of spermatozoa. In both groups, motility, progressive motility, kinematic parameters (VCL, VAP, VSL, STR, LIN, WOB, ALH, BCF), viability, and plasma membrane integrity were analyzed following thawing and after the thermal resistance test. Initially, no significant differences were found between groups in terms of motility and kinematic parameters; however, viability and membrane integrity were significantly higher in the rapid thawing group (P