Transported Stallion Semen and Breeding Mares with Cooled or Frozen-Thawed Semen

Horse owners worldwide now request that their mares be bred with cooled or frozen-thawed transported semen, owing to the advantages of avoiding mare transport (often with a foal by her side), decreasing disease transmission between farms, and most importantly, the accessibility to a wider genetic pool. This has become commonplace practice as many breed registries now allow the use of transported semen for producing foals worthy of registration. However, problems arise as optimal steps for both semen handling and preparation, as well as for mare breeding management, are not practiced. Therefore, the objective of this manuscript is to provide veterinary practitioners with an overview about optimal management techniques related to both handling semen and mare management for attaining successful results. Common problems and dilemmas encountered will be also discussed and emerging research introduced. Whereas appropriate protocols for handling and preparing semen for cooled-transport will be presented with some detail, it is beyond the scope of this paper to discuss stallion semen cryopreservation, which typically requires extensive equipment investment and expertise and is usually done at referral and specialized centers. This text assumes that the equine veterinary practitioner already has some basic skills in regards to stallion semen collection and evaluation, as well as in performing examination of the mare via transrectal palpation and ultrasonography for breeding management purposes.