Advances in deep uterine insemination: a fruitful way forward to exploit new sperm technologies in cattle

摘要

After clarifying regions of the female tract wherein spermatozoa are stored and the egg is fertilised, proposals are made for a modified site of sperm deposition in cattle. A deep pre-ovulatory insemination into the ipsilateral horn of the uterus-the side of the ovulatory follicle-should improve establishment of viable spermatozoa in the caudal region of the oviduct isthmus, the so-called functional sperm reservoir. Suppressed motility within viscous secretions and binding of sperm heads to endosalpingeal microvilli are features of this phase of storage. Activation and release of such spermatozoa would be prompted by imminent ovulation and associated ovarian endocrine programming by both local and systemic routes.