Site of semen deposition in cattle: A review

The breeding of cattle using conventional artificial insemination methods i nvolves the deposition of semen in the uterine body. However, it has been r ecently proposed by several authors that the site of semen deposition be ch anged to the uterine horns. This suggestion is based on 2 facts: the accept ance that the major preovulatory sperm reservoir may be the uterotubal junc tion rather than the cervical canal, and the lack of accuracy by inseminato rs in depositing semen. In over 50% of cases, inseminators were not suffici ently trained to deposit semen into the uterine body, so that intracervical insemination was often performed resulting in reduced fertility. The advan tage of deep uterine insemination, whether bicornual or unicornual, is that it favors the deposition of semen nearer to the uterotubal junction and th us reduces the incidence of cervical deposition. This review updates the li terature on the ideal site of semen deposition, including cervical, uterine body, cornual and intraperitoneal. Also analyzed are the effects of right vs. left side activity of the female reproductive tract on the optimum site of semen deposition as it affects fertilization. Finally, the question of whether the clinical training of inseminators should be reevaluated is disc ussed. (C) 2000 by Elsevier Science Inc.