Low Sperm Motility Is Determined by Abnormal Protein Modification during Epididymal Maturation.

Irregular modifications of mitochondrial proteins during epididymal sperm maturation may increase excessive ROS production and premature activation of spermatozoa during epididymal maturation. Consequently, spermatozoa may lose their motility by the earlier consumption of their energy source and may be damaged by ROS during epididymal maturation, resulting in a decline in sperm motility and bull fertility.