Written by Dr Fiona Lacey

The first equine pregnancy obtained from frozen semen dates back over 50 years. In recent times, breeding your mare with frozen semen has become increasingly popular in Australia.  Benefits of using frozen semen include having access to stallions from different countries and breeding from stallions that may be ill, injured or deceased. Breeding your mare with frozen semen can yield successful results but it requires the right mare selection, careful mare management and the proper use and selection of good quality semen.

From the stallion’s perspective, spermatozoa from some stallions do not tolerate the freezing and thawing process well. Consequently, post-thaw motility and pregnancy rates can vary greatly between stallions. This makes it important to know the post-thaw characteristics of semen prior to purchase.

Mares bred with frozen semen tend to have a lower conception rate than those bred with fresh or chilled semen. Mares that are ideal candidates for breeding with frozen semen are young (<14yo), reproductively sound mares that are either maidens or proven breeders. If you do decide to use frozen semen in an older mare with a history of being a “difficult breeder” you will significantly decrease your success rates.

Prior to breeding with frozen semen, your veterinarian should carry out a thorough breeding soundness examination. This will include :
  • 1. Checking the overall health and body condition of the mare,
  • 2. An examination of the external genitalia 
  • 3. Ultrasonography of the uterus and cervix per rectum and  
  • 4. A vaginal examination.  Mares that accumulate fluid in their uterus or those that have had bacteria isolated from uterine swabs should be treated appropriately prior to breeding with frozen semen.

From a veterinary perspective, breeding a mare using frozen semen requires intensive management. Consequently, the cost associated with breeding from frozen semen is higher than those using fresh or chilled semen.  As part of the management program, ultrasound examinations are performed every  2hrs are to ensure the mare is inseminated as close to ovulation as possible. In order to achieve optimum results, it is important that your veterinarian be experienced in handling and using frozen semen.

Whilst several factors require careful consideration when deciding to use frozen semen, mare selection is paramount. By following a few simple guidelines outlined in this article, frozen semen can be used very successfully in a breeding program.

If you have any questions, please feel free to call Olive Grove Equine Clinic on 9571 3992 or email info@ogec.com.au