Effects of dead spermatozoa on motion characteristics and membrane integrity of live spermatozoa in fresh and cooled-stored equine semen.
Overview
Research
Identity
Additional Document Info
Other
View All
Overview
abstract
The aim of this study was to determine if dead spermatozoa reduced motility or membrane integrity of live spermatozoa in fresh and cooled-stored equine semen. Three ejaculates from each of three stallions were centrifuged and virtually all seminal plasma was removed. Spermatozoa were resuspended to 25 x 10(6) spermatozoa/ml with EZ-Mixin CST extender and 10% autologous seminal plasma, then divided into aliquots to which 0 (control), 10, 25, 50, or 75% (v/v) dead spermatozoa were added. Dead spermatozoa preparations contained 25 x 10(6) spermatozoa/ml and 10% seminal plasma from pooled ejaculates of the three stallions, in EZ-Mixin CST extender. Spermatozoa were killed in the pooled ejaculates by repeated freezing and thawing, then stored at -20 degrees C until warmed to 37 degrees C and mixed with aliquots of fresh spermatozoa to be cooled and stored in an Equitainer for 24h. Motion characteristics (% total motility (MOT), % progressive motility (PMOT), and mean curvilinear velocity (VCL)) for fresh and 24h cooled samples were determined using a computerized spermatozoal motion analyzer. The presence of up to 75% dead spermatozoa did not adversely affect MOT or PMOT of live spermatozoa in either fresh or cooled-stored semen. However, VCL and the percentage of membrane-intact spermatozoa were reduced compared to control samples when 75% (v/v) dead spermatozoa were added. Membrane integrity, as assessed by staining with carboxyfluoresein diacetate-propidium iodide, was highly correlated (r>0.8; P<0.001) with MOT and PMOT in both fresh and cooled-stored semen samples. Results of this study have application to the processing of both cooled and frozen equine semen.
