Equine reproduction articles - CASA Screen

Cooled Semen Extender Evaluation Service

Facts about cooled semen extenders and your stallion

  • Not all stallions have sperm that will respond the same to all extenders;
    • Not only do different extenders have different ingredients, but there can be a difference in the response you see from your stallion’s sperm to different antibiotics used within those extenders!
  • There is no “best” extender that will work for all stallions;
    • The extender that happens to be the one most used by your semen collection service may not be the best for your stallion!
  • It is important if one is shipping semen to make sure that the extender being used is the most suitable for that stallion;
    • The extender that worked best for your stallion’s semen last year may not be the extender that works best this year.
  • There may be other factors that can have an impact to improve sperm survival rates that may not be noticed by less experienced personnel.
  • It can be time-consuming and expensive to perform evaluations on-farm where only a small portion of multiple extenders will actually be required, and the rest may be discarded;
    • Not everyone has the experience and equipment to perform an accurate evaluation of the cooled semen.
  • The time to find out which extender is best for your stallion (or that the extender that you used successfully last year is no longer suitable) is before you ship the first (dead) sperm shipment of the season to a mare owner!
We offer this service performed for you by us!

The Process:

Spring Pre-breeding Evaluation

Equitainers set up for a spring pre-breeding season evaluation

We will send you a variety of semen extenders and suitable packaging, you extend portions of an ejaculate in different extenders (following the directions we provide) and ship the semen to us in an Equitainer® (which you provide, although we can rent you one) via overnight courier. Note that we will not provide this service for semen shipped in disposable containers of any sort.

We will evaluate the quality of the shipment we receive at 24 hours*, 48 and 72 hours (if suitable) after collection and provide you with a written report for the following parameters:

  • Actual sperm concentration upon receipt;
  • Total sperm number upon receipt;
  • Sperm morphology at 24 hours* (standard 100+ sperm evaluated);
  • Live-dead percentages at 24 hours* (standard 100+ sperm evaluated);
  • Percentage progressive motility and velocity cooled and warmed (at 24*, 48 – and 72 hours if suitable);
  • Recommendations for changes (if any) that may improve the overall quality of the shipment.

*Or upon receipt, whichever is latest.


Cooled Semen Extender Evaluation Service performed with CEROS CASA by HRI
Sperm motility evaluations are performed using our
Hamilton-Thorne CEROS Computer Assisted Semen Analyser!
CASA Screen

The Protocol:

  1. Notify us that you are desirous of sending us a shipment for evaluation – we can then advise and confirm of final arrangements;
  2. Collect your stallion 3-4 days prior to the date that you intend collection for shipment to us. This will provide slightly fewer “old” sperm in the ejaculate sent to us, and possibly improve results. This is especially important with older stallions or early in the season – note that collection closer than this time frame may result in fewer sperm in the ejaculate and could therefore be undesirable;
  3. On the day of shipment to us, collect, extend and pack your semen following the directions that we provide;
  4. Send the semen to us, and await your results!

The Costs:

The charge for the evaluation service is $350.00

All shipping charges for our cooled semen extender evaluation service – to and from our facility – will be in addition, as will rental of an Equitainer® (if required). Overnight courier or airline counter-to-counter shipment is required to our facility, and ground or USPS shipment is recommended for the return of the container. If counter-to-counter shipment to us is desired, there will be an additional courier charge for pick up at the airport and transport to our facility.