Effect of video capture time on sperm kinematic parameters in breeding boars

Computer Assisted Semen Analysis (CASA) technology is being a common tool in the seminal analysis for seminal doses production in farm animals. The aim of the present work was to define the optimal capturing time for a correct evaluation of boar sperm motility. Six sexually mature boars from the Topigs Lines, were used as semen donors. ISASv1 CASA-Mot system was used with an image acquisition rate of 50 Hz for two seconds capturing. Obtained video frames were fragmented into four segments corresponding to 0.5, 1.0, 1.5 and 2.0 s. ISASD4C20 counting chambers, warmed at 37 °C were used. Total and progressive motility were not affected by capture time. Capture time had a significant effect on velocity and indexes values (P < 0.05) but not on lateral head displacement (ALH) and beat cross frequency (BCF). All the parameters showed animal differences. The results demonstrate that sperm motility is affected by the video recording time length (P < 0.05). This effect is evident both in motility parameters and in single cell kinetics, studied by cluster analysis that showed a short time of video recording can to overestimate the percentage of very rapid progressive cells in a subpopulation (P < 0.05). Studies based just on motility can use one-half second, while when kinematics must to be considered two seconds must be analyzed.