The Influence of Different Seasons on the Motility and Kinetics Parameters of Deep-frozen Semen in Simmental Bulls

Abstract

The aim of the research work was to study the influence of seasons on sperm motility and kinetics parameters of deep frozen semen in Simmental bulls. The study included 43 bulls whose semen was collected and deep-frozen during the summer, autumn, spring, and winter. The semen was analyzed using computer-assisted semen analysis (CASA), whereby 0.25 mL straws were thawed in a water bath at 38 °C for 20 seconds. Present study revealed that the season had no effect on sperm concentration, total and progressive motility, the percentage of fast and slow sperm, sperm moving in circles or in place, or immotile sperm (p > 0.05). Additionally, no seasonal effect (p > 0.05) was observed on sperm kinetic parameters: velocity curved line (VCL), velocity straight line (VSL), velocity average path (VAP), distance curvilinear line (DCL), distance straight line (DSL), distance average path (DAP), amplitude of lateral head displacement (ALH), head activity (HAC), wobble (WOB), linearity (LIN), and straightness (STR). Further, it was revealed that the values for beat cross frequency (BCF) were found to be only season-dependent, showing significantly lower values when semen was collected and deep-frozen during the summer compared to spring and winter (p < 0.05).