Cryopreservation of Equine Semen with a Mechanical Control Rate Freezer

With the evolving use of assisted reproductive technologies (ART) in the equine industry, there is a need for a cost effective, field method of preparing stallion semen for cryopreservation. Currently, semen is either suspended in the mist above liquid nitrogen or frozen in an electronic controlled rate freezer (ECRF). Mist freezing (VM) has an uncontrollable temperature drop, increasing damage to cells. ECRF yields superior results, yet is cost prohibitive and complex to use. The current study explored the use of a new mechanical controlled rate freezer (MCRF) in a control environment. Samples for cryopreservation where obtained from 15 stallions, and frozen using MF, ECRF or MCRF. Once thawed, the samples were analyzed for standard semen parameters using a computer assisted semen analyzer at 0 and 3 hours post thaw, additionally morphology and acrosome slides were prepared. Initial post-thaw analysis demonstrates rapid cell movement in both MCRF and ECRF; but not MF. Further, morphology from MCRF and ECRF correlate with stallion standards. With current data, the MCRF appears to produce higher quality samples than MF and comparable to ECRF.