Why Should I Freeze My Stallion's Semen?

Why should I consider freezing my stallion’s semen?

There are many reasons stallion owners should consider freezing their stallions’ semen. Here are a few:

  • It allows for the national and global marketing of your stallion's bloodlines.
    • With fresh cooled semen, fresh semen, and live cover, you are more limited geographically in the marketing of your stallion’s genetics. With fresh cooled semen, ensuring next day delivery to a barn across the globe is difficult to impossible to promise. Fresh semen and live cover require actual proximity with the mare, which can cause a lot of stress on the stallion or mare, and their owners. With frozen semen, you can freeze far in advance, and ship far advance. The mare owner can order the semen ahead of time and store the frozen semen on premises until the mare is ready for insemination. From a purely administrative and logistical perspective, frozen semen is easier and has less room for error. Irongate Equine Clinic can also handle the complex import requirements for equine semen shipments.
  • It cuts costs for mare owners, making your stallion more desirable.
    • The cost of shipping an equitainer with frozen semen is far more cost efficient than shipping a stallion or mare. Improving convenience to the mare owner, or at least offering multiple options from your stallion, improves desirability and availability.
  • It increases the volume of breedings possible for your stallion.
    • Again, logistically, frozen semen makes a lot of sense for a stallion owner. As anyone in the breeding business knows, a mare becomes ready on her own time, and often that time is inconvenient. If your stallion is in the show ring, he often won’t be available for on demand breedings during prime breeding season, which inconveniently coincides with show season. Your stallion may also be on a strict collection schedule to ensure the highest quality collections – a mare’s need for fresh or fresh cooled semen can interfere with that schedule and lead to behavioral and quality problems for your stallion. Other problems including injury, multiple mare owners requesting collections simultaneously, weather, or even simple moodiness of the stallion. Collecting ahead of time and freezing your stallion’s semen gives you a back-up plan.
  • It preserves the genetic potential of your premier stallion against future loss.
    • Unexpected Loss – Our ability to freeze semen means you have the ability to preserve the superior genetics of your stallion. If your stallion is hurt, passes away, or is sold, you have insured your future by freezing that genetic potential. Prior to beginning the freezing process, make sure to check with your breed registry on whether or not you continue to own that frozen semen after your stallion is sold, and if foals by frozen semen can be registered. Each breed registry has their own rules and regulations.
    • Stallion Aging – We’ll sometimes have stallion owners approach us as their premier stallion ages, and begins losing fertility. Thinking about this potential early on in his career can protect against that loss. Spermatozoa from a younger stallion is frequently better able to withstand the stresses of the freezing process.
    • Gelding – Frequently, we’ll have stallion owners ask to have their stallion collected and frozen prior to being gelded. Your stallion may have behavioral issues which you hope to control through gelding, needs to focus on his show career, doesn’t have the mindset for the dual role, or you have a barn management concern with having a stallion on the property. Oftentimes, a talented gelding is worth more in the marketplace than an equally talented stallion because of the above-mentioned factors. Freezing your stallion’s semen gives you an opportunity to look after your best interests and have your stallion’s future ensured.

How do you freeze semen?

To start with, your stallion should be collected regularly, or, alternatively, have a number of “clean-out” collections to ensure we process the fewest number of stored sperm cells during freezing. Stallions are producing sperm cells constantly, and stored sperm cells are less able to withstand the rigors of the freezing process. By collecting your stallion a minimum of two to three times to “clean him out”, we’re getting as close as possible to his daily sperm production. This will enhance the post-thaw quality. After cleaning out your stallion, we’ll collect him in the typical fashion using a “phantom mare”. The semen is then centrifuged to concentrate it and remove the seminal plasma. The concentrated semen “pellet” is then re-extended in a specifically-formulated freezing extender. This extender contains one of several types of cryoprotectants that protect the sperm cell as it goes through the freezing process. The extended semen is then split into as many straws as necessary to meet current industry standards. The straws sit over liquid nitrogen vapors to slowly decrease the temperature, after which they are placed in the liquid nitrogen and stored for an infinite time, as needed.

Currently, the industry standard is to package semen in 1/2 cc straws, with multiple straws per dose of semen. The number of straws is dependent on that stallion’s post-thaw motility and the specific freezing protocol. Each dose should contain somewhere between 200 to 250 million progressively motile sperm cells. To get to that number, we could package up to one billion cells, have a 30% progressive motility post-thaw, and achieve the 300 million progressively-motile cells per dose of semen.

That frozen semen is then available to be used forever. There is no time limit on when it needs to be used by, at least not one that we’ve run into yet. Dr. Griffin is still getting foals out of semen from Abdullah, the great Trakehner stallion that was foaled in 1970 and passed in 2000. That semen dates from the 1990’s, and is producing as well as ever.

While the process sounds simple, there are a huge variety of man-made mistakes that can decrease fertility and cause error in the freezing process, as well as all of equine reproduction. All of the equipment that the semen contacts need to be at the appropriate temperature – a lack of temperature consistency is one of the easiest ways to decrease success in freezing semen. Use of a high quality semen extender is imperative, as well as protection from light and toxins that come from non-sterile equipment.

Who, Where, When?

Dr. Pat Griffin graduated from Colorado State University with his Bachelor’s of Science and Veterinary degree prior to moving to Madison. At the University of Wisconsin-Madison, he completed his Master’s and PhD in Reproductive Physiology before earning his board certification with the American College of Theriogenologist’s. Dr. Griffin is one of four practicing board-certified theriogenologists specializing in equine reproduction in Wisconsin.

We offer full service reproductive work, and we take care of all of the details for you. We can collect your stallion either at our breeding shed in Waunakee, or at your farm in the south and southeastern Wisconin area. We can board your stallion at the barn while completing a series of collections, provide the tease mare (affectionately named “Crooks”), the phantom mare and training, as needed, and can store the frozen semen after collections are complete. When you’re ready to ship doses out to the mare owners you contract with, we’ll take care of the shipping, billing, and import requirements as needed.

Like we said in the beginning, freezing your stallion is convenient. Dr. Griffin is the only boarded equine reproductive specialist in Wisconsin that offers semen freezing year-round, and we can do it anytime. Many stallion owners prefer to collect and freeze during the fall and early winter to avoid show season, and we’re happy to help. Just Contact Us and we’ll get you in touch with Dr. Griffin to discuss the process.

Questions? Call us, or leave a comment below. We’ll get back to you!

By Pat Griffin, DVM, PhD, DACT