Sperm DNA damage causes, assessment and relationship with fertility: A review

Evaluation of sperm quality has been mainly based on subjective parameters included in the spermiogram. Results of these parameters have been correlated with fertility but this relationship is not always true. Recently, for bull fertility assessment, sperm DNA integrity assessment has been proposed as an important index. Sperm DNA integrity has got an important role in success of fertilization process and fetal and offspring development. DNA integrity assessment has got a pivotal role in assisted reproductive techniques such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), besides sperm quality assessment and putative fertility predictor. Various techniques for assessment of sperm DNA integrity have been proposed. Using various sperm DNA integrity assays for detection and characterization of DNA fragmentation will aid in improving semen storage procedures by identification of various protocols which are less likely to be associated with DNA damage. Moreover, sperm DNA assays may help in screening bulls that produce good freezable semen with reasonable fertility.