There is a significant amount of variation in the composition and protein profile of seminal plasma between individual males and across the male lifespan. This individual variation creates potential for the transfer of sperm kinetic traits from one male to another through inter-male seminal plasma supplementation. However, previous studies isolate spermatozoa and re-supplement with seminal plasma, adding an additional, sperm-damaging step to common assisted reproductive technology protocols. As a more efficient alternative, the present study supplemented fresh whole ejaculates with additional seminal plasma to investigate overall effects and inter-individual interactions. It was found that supplementation of ejaculates with seminal plasma increased overall sperm motility and had varying effects on sperm velocity and hyperactivity depending on the ram. The difference between donor and receiver motility and hyperactivity influenced the amount of change in these traits, but the same relationship was not seen for velocity. These findings indicate that seminal plasma plays key roles in the control and regulation of sperm motility and hyperactivity and demonstrated the flow of sperm kinetic traits from one ejaculate to another through seminal plasma supplementation of whole ejaculates.
assisted reproductive technologies, inter-individual variation, ovine.