Casa based assessment of post-thaw sperm motion traits as fertility indicators in Mehsana buffalo bulls

Abstract

Computer Assisted Semen Analysis (CASA) enables efficient and objective evaluation of large numbers of spermatozoa, supporting semen quality assurance for artificial insemination. This study compared CASA-derived motility and kinematic parameters of frozen-thawed semen from 12 Mehsana buffalo bulls classified as high-fertile (CR ? 43%) or low-fertile (CR ? 35%) based on field conception rates. Motility was assessed at 0, 10, 60 and 120 minutes of post-thaw incubation at 37°C using the Hamilton Thorne IVOS II CASA system. Total and progressive motility declined significantly (p<0.05) with incubation time in both groups and remained higher in high-fertile bulls. Velocity parameters (VAP, VSL and VCL) were significantly higher (p<0.05) in high-fertile bulls at 0 minutes, increased at 10 minutes, and subsequently declined over time. Correlation analysis revealed positive associations of VAP, VSL and straightness with progressive motility, highlighting their potential as fertility indicators in Mehsana buffalo bulls.