Breeding Chronicles Part I: Considerations When Deciding to Breed My Mare

Maria with her mare Sky
Maria with her mare Sky

Like many of us at The Cheshire Horse, I am an active equestrian who absolutely loves spending time in the saddle. I grew up competing in 4-H and local fun shows, later turning my focus to Cowboy Mounted Shooting! Additionally, I recently became a mother to an active 1-year-old son, Lane. While managing the duties of working motherhood (and being a horse-crazy woman!), I decided to add a bit more excitement to the mix. I am planning to breed my mare this spring. I would like to invite you to join me on this new adventure in my blog series, where I explore just what it takes to welcome a new bundle of equine joy into the world.

I am joined on this exciting venture of breeding my mare by my mother. My mom is truly the reason that I am involved in horses and we have always enjoyed them together. She has always had a passion for horses and passed that love on to me. As a youngster, she often walked to the nearby fairgrounds and cleaned stalls, simply to be around horses. From there, she grew up around horses and introduced me to that passion at a young age.

I was lucky to grow up on a 10-acre farm where we kept our horses. They were truly our pets! I became actively involved in the show scene, and my mom continued to support me every step of the way. Together, we are excited to breed my favorite mare next season.

Sky

My mare AR Skylines Highbrow (Mr Skyline Peppy x Kats Dainty Gal), also known as “Sky,” is a 12-year-old Quarter Horse mare registered with the American Quarter Horse Association (AQHA). She is a stunning sorrel with four white socks and a star. Her sire and dam are both money earners in cutting, although Sky and I typically compete in the cowboy-mounted shooting events. Sky is extremely versatile and has a quiet mind; I can teach beginner lessons on her one day and then run her in a mounted shooting event the next, she takes it all in stride.

There were a lot of considerations that my mother and I made before we decided to start this breeding journey with Sky. She is well-bred, has excellent conformation, and has a wonderful disposition. We have also been fortunate to be able to study Sky’s past progeny since we own a four-year-old colt out of her by Fly The Red Eye (a running bred horse), who was born via embryo transfer (ET).

An embryo transfer takes the embryo (typically a fertilized egg seven or eight days after conception) from the uterus of one mare and implants it into the uterus of another mare, referred to as the recipient mare. The recipient mare then carries the foal to term, and in turn, delivers and cares for the foal. ETs are done for a variety of reasons, including allowing the mare to continue competing or have more than one foal a year. They are also frequently done with older mares with whom it may be risky to have them carry a foal to term. In my case, we chose to use a recipient mare because Sky and I spent our summer in Jackson Hole working on a dude ranch that year.

Additionally, we have performed a five-panel genetic test to ensure that she was not a carrier of possibly fatal and debilitating diseases. The results of this testing are now attached to her permanent record and registration papers. Performed and processed through AQHA and the Veterinary Genetics Laboratory at the University of California-Davis, the five-panel test is a simple test utilizing a hair sample to look at genetic markers that would indicate she if carried the following diseases:

  • Glycogen Branching Enzyme Deficiency (GBED): According to the AQHA, “The mutation of the GBE1 gene reduces the function of the glycogen branching enzyme so that cardiac and skeletal muscle, the liver, and the brain cannot store and mobilize glycogen. Because glycogen provides energy to the muscles, the inability to properly store and mobilize it leads to muscle weakness and eventually death. GBED results in second-and third-term abortions and stillborn foals.”
  • Hereditary Equine Regional Dermal Asthenia (HERDA): This gene mutation causes defective collagen, which results in the outer layer of skin detaching from the interior layer. Commonly, the skin sloughs off and the impacted horses have large, slow-healing sores on their body.
  • Hyperkalemic Periodic Paralysis (HYPP): Tracing back to the stallion Impressive and his get, this mutation causes the impacted horses to have severe muscle tremors and even partial paralysis.
  • Malignant Hyperthermia (MH): Horses with MH are not able to regulate the amount of calcium released into the muscles. “Affected horses experience increased muscle metabolism, fever often exceeding 109 degrees F, excessive sweating, high heart rate, abnormal heart rhythm, shallow breathing, hypertension, muscle rigidity, breakdown of muscle tissue, muscle protein in the urine, and/or death,” explains AQHA.
  • Polysaccharide Storage Myopathy Type 1 (PSSM1): PSSM1 results in excess sugar in the muscle cells. This makes it difficult and extremely painful to move, while also causing excessive sweating, weakness, and exercise intolerance.

After doing our due diligence as responsible breeders, my mother and I are excited about our decision to breed Sky in the spring of 2022. We are still in the process of selecting a stallion. We are looking for a well-rounded, athletic stallion who will complement Sky and her conformation. I am breeding for a versatile Quarter Horse who is a great mover and able to compete in a variety of venues.

The timing is great for us, I will still be able to compete off of her this year and then I will begin focusing on her current colt, Jackson, in the spring. I am excited to help him reach his full potential while we patiently await the arrival of his siblings. 

The next step to breeding Sky is selecting the stallion and preparing for the breeding. I hope that you will continue to follow along on our journey!

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