Once equine semen is frozen it is recommended that a post-thaw analysis be performed in order to ascertain the semen quality. There is variability in how well sperm from different stallions respond to the cellular stress of freezing and thawing. It is important to determine how well the sperm from a particular stallion withstood the stress of cryopreservation in order to make informed decisions regarding the management of their frozen semen inventory and breedings. Also, when we freeze a stallion for the first time we do a test freeze comparing several different protocols. We then use the post-thaw motility to select the freezing protocol for subsequent collections which gives the best post-thaw result. There are industry recommended minimums for commercial distribution of equine frozen semen and therefore it is pertinent to know if your stallion’s frozen semen would qualify. Consequently, the analysis of frozen-thawed semen is a valuable tool for the semen freezing lab, but also for the veterinarian receiving the semen. Your vet may base the breeding management of your mare upon the post-thaw quality of the semen. Also, many vets take a look at the motility of the frozen semen at the time of insemination, for future reference if there are concerns should the mare not check in foal.
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Analysis of Frozen-Thawed Equine Semen
Effect of Number and Timing of Equine Frozen Semen Inseminations on Fertility
Further expansion in the use of frozen semen is dependent upon developing simplified strategies for insemination. SBS has developed a timed insemination protocol where mares are only examined once per day during estrus and inseminated at 24 and 40 hr after hCG or 30 and 40 hr after GnRH. This approach allows frozen semen mares to be managed similar to those bred with cooled shipped semen. A couple of arguments against this approach with frozen semen is that it takes too much semen when mares are bred twice in one cycle and that if the mare is inseminated more than once per cycle the fertility will be lowered because of post-breeding induced endometritis.
Quality Control is at the Core of the SBS Difference
The SBS network of affiliates is the acknowledged leader in the field of cryopreservation of equine semen. Each year we freeze thousands of ejaculates equating to tens of thousands of doses. In fact, this year the SBS Network will surpass the 50,000 ejaculate milestone since the company’s founding in 1987. When SBS was founded the company leadership made a commitment to quality of the finished product above all else. We wanted to put technology to use to help grow the equine frozen semen AI industry in the most responsible manner possible. It was clear early on that one of the major factors limiting the application of frozen semen in the horse industry was inconsistent quality of the product being put on the market. Breeders and veterinarians experienced frustration with attempts to use expensive semen that in many cases was of very poor quality. We knew that in order for breeders to realize the full potential of frozen semen technology they would have to be convinced that by applying strict standards for quality, frozen semen could be produced to achieve results similar to cooled semen. We also knew that these results would have to be produced in an efficient and economical way. Quality became the cornerstone upon which we would build our business.
Splitting Doses of Frozen Semen
“I just purchased one very expensive dose of frozen semen from this incredible stallion. Is it OK to split the dose and breed two mares to try and get two foals?” or “The stallion owner only provides one dose per heat cycle and my vet would like to use a timed insemination protocol. Is it OK to split the dose and inseminate twice on the heat cycle?” At SBS we have heard these questions or some variation of them many times over the years. The answers are not simple ones. This blog article will follow up on two previous blogs that are also important in understanding the issue. See the recent blogs What Exactly is a Dose of Frozen Semen? and What is Progressive Motility?
What Is Progressive Motility?
The most commonly used measure of semen quality is sperm motility, specifically “progressive motility”. But what exactly does that mean and how is it determined? The minimum post-thaw “progressive motility” generally recommended for commercial distribution of frozen semen is 30% to 35%. This article will address some of the factors that can affect the assessment of sperm motility as well as the various problems associated with techniques used for determining “progressive motility”.
What Exactly is a Dose of Frozen Semen?
Is a dose a breeding? Is a straw a dose? How many straws in a dose? How many sperm in a dose? These are often questions we hear from our clients when purchasing or using frozen semen. There is so much variability in the format of doses sold throughout the world that it can be confusing at times. To ensure you have the best opportunity of success when breeding your mare it is important to understand all the elements that determine an adequate dose of frozen semen. Here we review frequently asked questions that relate to what constitutes a dose of frozen semen.
Understanding Your Frozen Semen Shipment Transaction Report
Every shipment that we send from Select Breeders Services includes an envelope of materials, zip tied to the top of the frozen semen shipper, that provides information about the semen we are sending to you. Included in the envelope are the following items:
- Transaction Report
- Safety Notice for Handling Frozen Semen
- Thawing and Handling Instructions
- Info sheet on Management of Mares with Frozen Semen
- Return FedEx airbill and address label
- Info notice regarding tank rental and return
- Additional materials may include notices prepared by the stallion owner that they have requested us to include with the shipment, e.g. breeding and insemination certificates.