Cryopreservation and Use of Frozen Semen in Sheep Reproduction

Abstract

Cryopreservation of ram sperm has been in development for decades. The reason is that ram sperm is more vulnerable to any external factors than sperm of other species. Every step of the process of preserving ram sperm needs to be done carefully to avoid causing unnecessary damage. It starts with possible semen collection methods all the way through lambing after insemination with the collected and preserved semen. This process has its advantages over using natural mating, however, there are disadvantages at the same time. The selected preservation method can be influenced by the preferred insemination method, and vice versa. Substances used for dilution of semen can be combined in many ways but it has to be done carefully, not to cause harm to spermatozoa. Vaginal insemination is considered to only be successful with fresh semen, while cryopreserved semen can only show acceptable success rates when deposited directly into the uterus.