Breeding with Cool Shipped or Frozen Semen

Artificial insemination of mares can be very successful if done right. There has to be a close working relationship between the mare owner and the stallion owner. The stallion owner has the first obligation. He must collect the stallion, test him, and know that he is shipping a viable sample that will be effective if the recipient mare has been prepared properly and is ready for breeding.

The stallion owner should collect the specimen and make a count on the semen at each collection and shipment. He should know and report to the mare owner the number of sperm in that particular ejaculate and the number of sperm that is being shipped. It needs to be mixed at least three parts extender to one part strained semen. It is preferable to have an antibiotic in the extender to provide safe shipment. The stallion owner should fill out a report and send with the shipment telling the number of cc of semen collected, the motility of that sample, the count of sperm per cc of that sample, the extender, and the ratio mixed for the shipment. He may also send you a test run that gives you the motility reading of a test sample based on 24, 48, and 64 hour motility counts based under cooled storage. This is not as important if there is a running record of the stallion’s success on settling mares with shipped semen.

The mare owner has the responsibility of finding as good a reproduction veterinarian as possible. They are hard to find, but working with a vet that is equipped with knowledge of reproduction as well as experience with reproduction of heavy horses and a willingness to cooperate in this procedure will be helpful.

The one thing to remember is that heavy horses differ in some of their reproductive responses from light horses. They are much more deliberate with their follicles and how long they will hold them. They also retain a much, much larger follicle that do the light breeds. The key to the artificial insemination process is to know when the follicle drops. After the mare is bred, she should be checked in 6-24 hours to see if she actually has dropped the follicle. If not, then a second breeding may be in order. The cooled shipped semen can stay active for about 48 hours after collection. That leaves a big window to hit in breeding the mare.

A good reproduction veterinarian is very important for the mare owner. He can save a lot of time, frustration, and expense if his timing is accurate.

Overnight shipments can be made, so if you inform the stallion owner of your upcoming needs, he can ship the next day and it will usually arrive by 10 or 12 AM the following day. Timeliness in both the shipment as well as the breeding is essential for the success of the project.

Frozen semen is handled much differently and needs even more expertise to be successful. It will, however, become the preferred method of breeding as soon as we learn more about frozen equine semen and our veterinarians become more skilled in determining the follicle drop on the mare. One advantage is that the frozen semen can be held at the site of the mare owner for an indefinite period of time before it is used. The timing of breeding is much more critical and should be used within six to twelve hours of follicle drop.

Copyright © 2010 Jenson American Shires
Last modified: 07/10/11