Breeding Mares with Frozen Semen in Private Practice

In the last decade several registries have approved the use of frozen semen commercially. With the recent approval by AQHA, the largest horse registry in the country, to use frozen semen, it is expected that inseminating mares with frozen semen will become a common procedure. There are several advantages in using frozen semen. Among them are the following: 1) transportation of a nitrogen tank is less expensive than transporting the mare, 2) semen is continuously available at the mare site, 3) insemination can be timed more closely to ovulation, 4) the genetic pool can be increased, and 5) semen properly frozen and stored will be available for several decades. Despite advantages, disadvantages include the following: 1) lower pregnancy rates from some stallions, 2) increased breeding costs to the mare owner because of an increase in veterinary examinations, 3) wide variation in semen quality, and 4) lack of standard protocols for breeding mares with frozen thawed semen. Veterinarians using this technology must be aware of the procedures needed to maximize pregnancy rates with frozen semen and understand the factors that affect fertility of frozen semen so that they have realistic expectations for themselves and the stallion and mare owners. The objective of this paper is to describe a veterinary practice that uses frozen semen. The facilities and equipment needed, factors affecting the success of frozen semen, insemination timing and technique, and mare management are topics discussed. Authors’ address: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506. © 2001 AAEP.