Zhila Bohlool - Ph.D Student, Animal Physiology, Gorgan University of Agriculture and Natural
Yousuf Jafari ahangri - Professor of Gorgan Agriculture and Natural Resources UniversityResources

Sperm cryopreservation contributed to the expansion of reproductive techniques, such as artificialinsemination (AI) and in vitro fertilization (IVF).It is essential to improve fertility rates in our nativebreeds, using insemination with frozen-thawed semen, either through the improvement of sperm cellscryopreservation or the control of female factors interfering with fertility. AI with frozen semen wasessential in breeding and selection schedules contributing to increase production of domestic species.It was shown in rams that frozen semen stocked during 27 years didn’t affect fertility, becomingpossible the preservation of semen cryopreservation. The cryopreservation of mammalian sperm was acomplex process that involves balancing many factors in order to obtain satisfactory results. To ensureeven minimal success, not only proper diluents, sperm dilution rate, cooling rate and thawing rate wererequired, but also an intricate knowledge of the sperm physiology for the species was essential tomaximize post-thaw.

Ram, Sperm, Fertility, Freezing