Impact of agitation time of boar semen doses on sperm traits in short- and long-term extenders

Abstract

Transport of extended boar semen doses is a common practice in the swine industry. This study aimed to verify the effect of agitation time on sperm parameters during storage in two semen extenders. One normospermic ejaculate from each boar (n = 20) was diluted in a split sample design with long-term (LONG, Androstar® Plus) and short-term (SHORT, Beltsville Thawing Solution) extenders. Extended semen doses were filled with a total volume of 45 mL and 1.5 billion sperm cells and submitted to 0, 3, 6, and 12 h of agitation in an orbital shaker at 70 rpm. The samples were stored at 17 °C for 120 h. Sperm parameters were evaluated for sperm motility, plasma membrane integrity, pH, thermo-resistance test (TRT), oxidative stress status, and mitochondrial membrane potential. Total and progressive motility were affected by the interaction between the agitation time and the extender, with a linear reduction in sperm motility as the agitation time increased for LONG extender (P ≤ 0.05). Semen doses diluted with SHORT showed a higher pH (P < 0.01), and agitation time had a positive quadratic effect with the highest pH observed after 6 h of agitation, regardless of the extender used (P < 0.01). Sperm motility after TRT and plasma membrane integrity potential were not affected by agitation time (P > 0.05). Mitochondrial membrane potential and oxidative stress status quadratically decreased as agitation time increased (P ≤ 0.05). Based on the results, long transport durations of AI doses under mild vibration emissions affect boar semen quality.