Differences in CASA output according to the chamber type when analyzing frozen-thawed bull sperm

•We compared the efficiency of three disposable chambers used for sperm examination.•Bull sperm were examined using SpermVision version 3.7.•MofA chamber offered better results immediately after filling.•Leja and Minitube chambers offered better results at 6 and 12min after filling.•All the three types offered lower values for concentration than standard methods. As demonstrated by some authors, the type of analyzing chamber can greatly influence the results of computer-assisted sperm analysis (CASA). This study aimed to compare three of the disposable chamber types currently available on the market and to determine whether the CASA output may be significantly different among them. The semen from five Fleckvieh bulls was analyzed by CASA using three different disposable chambers: Leja (20μm), MofA (20μm) and Minitube (20μm), at three different time points: immediately after filling the chamber, at 6min, and also at 12min after filling. Sperm concentration was also determined using the Nucleocounter® NC-100™ device and the hemocytometer as standard methods. The results showed higher values in terms of total and progressive sperm motility for MofA compared to the other two chambers immediately after filling (p