Hysteroscopic or rectally guided, deep-uterine insemination of mares with spermatozoa stored 18 h at either 5 or 15 degrees C prior to flow-cytometric sorting

摘要

Effective preselection of sex has been accomplished in many species of livestock following the development of a safe and reliable method utilizing flow-cytometry [1]. In mares, pregnancy rates of 38 percent have been achieved following hysteroscopic insemination of low numbers of flow-sorted sperm [2]. Unfortunately, hysteroscopic insemination is an expensive and technical procedure that is uncommon in the equine industry. Rigby et al. [3] obtained similar pregnancy rates following both hysteroscopic insemination (62 percent) and a more simple, rectally guided deep-uterine insemination (50 percent) when 5 x l06 cooled, shipped sperm were utilized. To commercialize flow-sorted sperm in the equine industry, it is necessary to develop a method for the shipment of stallion sperm prior to sorting. It has been proposed that maintaining sperm above the standard shipping temperature of 5 deg C may result in less damage to sperm membranes, and maintain greater viability throughout the flow-sorting process. The objectives of this study were: (1) to compare pregnancy rates after deposition of 20 X 10~6 flow-sorted sperm onto the uterotubal papilla with either a flexible videoendoscope or by rectally guided, deep-uterine insemination; and (2) to compare pregnancy rates resulting from insemination of sperm stored at either 5 or 15 deg C prior to flow-cytometric separation.