PS1-8. Sperm Motility Evaluation in Bulls Fresh Semen Using Two Portable Computer-assisted Sperm Analysis System.

Abstract Portable computer-assisted sperm analysis (CASA) systems have become increasingly popular for reproductive evaluations under field conditions due to their portability, accessibility, and lower cost compared with traditional laboratory-based CASA systems. These devices allow for objective assessment of sperm parameters including total motility, progressive motility, and sperm concentration. However, differences in hardware design, algorithms, and analytical procedures may affect measurement outcomes between systems. Therefore, evaluating agreement between these systems is important to determine whether their measurements can be used interchangeably in bull reproductive assessments. The objective of this study was to evaluate the agreement between two portable CASA systems (AndroScope [ANS] and iSperm [ISP]) for the assessment of sperm concentration, total motility, and progressive motility in fresh bovine semen. A total of 137 fresh semen samples were analyzed. Each sample was evaluated using two portable CASA systems under standardized field conditions. When needed, semen samples were diluted (1:10 or 1:100) using HEPES buffer (1X); the same diluted aliquot was used for both systems. Each diluted sample was evaluated three times per system, and replicated measurements were averaged for analysis. Differences between systems were evaluated using PROC GLIMMIX in SAS, agreement between methods was assessed using Bland–Altman analysis and proportional bias testing, and linear association between systems was evaluated using Pearson correlation coefficients. Significant differences between systems were detected for sperm concentration (ANS= 451.65 ± 860.80, ISP = 691.30 ± 102.50; P = 0.01), total motility (ANS= 73.81 ± 16.15, ISP= 22.59 ± 0.52; P < 0.01), and progressive motility (ANS= 45.06 ± 17.13, ISP= 23.00 ± 16.95; P < 0.01). Pearson correlation coefficients between systems were 0.75 for concentration, 0.36 for total motility, and 0.44 for progressive motility (P < 0.0001 for all parameters). Bland–Altman and proportional bias analyses revealed both constant and proportional bias between systems. iSperm increasingly underestimates values relative to AndroScope as magnitude of measurement increased. Although an association was observed for some parameters, the individual CASA systems differences indicate that the AndroScope and iSperm systems are not comparable across the evaluated measurement range.