A Mare Owner's Guide to the Use of Transported Semen

by Charlene Cook, DVM
(reprinted from May 1995)
© Copyright 1999, Voice of the Tennessee Walking Horse, Lewisburg, Tennessee

Imagine the possibilities. Your dream stallion is thousands of miles away, your mare is safe and sound in your barn at home and by using transported semen she can be bred without ever leaving the farm.
The possibilities are endless, the technology is here but to be successful you must prepare yourself and your mare.

Start by calling your veterinarian and explain that you would like to breed your mare by transported semen. You will be needing the skills of a veterinarian who handles reproductive work on horses. Your veterinarian will need to be able to determine the best time to order semen, to inseminate your mare and to determine her pregnancy status after the breeding. Your veterinarian will need to be able to come to your farm several times during the breeding process. Be sure to ask if weekends are a problem. If your veterinarian is not comfortable handling your mare's breeding you may wish to take her to a veterinary clinic or a breeding farm where there is skilled help available.

Here's the fun part, selecting a stallion for your dream foal. But before you make a commitment, ask a few questions. Ask the stallion manager if they offer transported semen. Ask what days of the week semen shipments are available and how much advance notice they need for a shipment. Ask how the shipments are sent (UPS, Federal Express etc.) and also ask if Same Day Air Service is available. Be sure to ask about the costs for collection, shipping and airport transportation. Find out if the breeder provides a container for shipping and if a deposit is required. Lastly, ask how many doses of semen you can expect per shipment and will the stallion be available during the entire breeding season or will he be unavailable due to horse shows or exhibitions.

Once you have made your selection, you will need to fill out your breeding contract, and make any required deposits, stud fee payments and shipping prepayments. Be sure to read your contract carefully and note any special requirements for the use of transported semen.

Now take a good look at your mare. She should be in good weight, not too fat and not to thin. I like mine "pleasingly plump". Before you breed her have your veterinarian do a thorough reproductive check-up including a rectal palpation, speculum examination and a uterine culture. Your veterinarian may recommend a uterine biopsy if your mare has a history of infertility. Don't forget to have her teeth checked, her vaccinations and deworming updated, and her feet trimmed. Think in terms of making her the best possible mother - healthy, sound and fertile.

Okay, you've done your homework and now it is time to make it work. You will need to get your mare in heat. One way is to tease your mare daily with a teaser stallion or gelding and wait on her to come in heat. A second way is to give her an injection of prostaglandin to bring her into heat. Most mares are in heat within 2 to 4 days after the injection. A third way is to "program" your mare's heat cycle. You start by giving Regumate (a liquid hormone) once daily for 15 days. On the 15th day, you also give an injection of prostaglandin. Most mares are in heat on the 19th day and ready for breeding on the 21st day. By using this program, you can literally pick a date on the calendar that you would like to breed. It is especially helpful in cases where the stallion will be unavailable due to shows or exhibitions. I normally start palpating on day 19 and order semen when I have a 3 cm follicle and a Grade 4 cervix. If your mare is foaling, you can expect her to be in foal heat approximately 9 days after foaling and again approximately 30 days after foaling.

Foal heat breeding is controversial at best. I use foal heats provided the delivery was normal with no complications, the placenta was passed within 60 minutes, and there has been no pus discharge. I normally examine the mare on day 7 after foaling to see if she has any bruising or signs of infection. If she has any bruising or infection, I recommend waiting for her 30 day heat.

Once your mare is in heat, your veterinarian will need to determine the best time to order semen. Most mares with a 30-35 mm follicle and a Grade 4 cervix will be ready to breed. In most cases, the semen will arrive the next morning and the veterinarian will inseminate the mare and administer a dose of HCG (Human Chorionic Gonadotropin) to ensure ovulation. The veterinarian should recheck the mare 24 hours later to see if she has ovulated. If she is still holding the follicle, the second dose of semen is inseminated. It is important the veterinarian check the mare 24 hours after her last breeding to be sure she has ovulated. If she has not ovulated, you will need to order more semen. Once she has ovulated, mark your calendar for a pregnancy check 16 to 21 days later. Be sure to return the container to the breeder as soon as you have removed your last dose of semen.

Editor's note: We'd like to voice our thanks to Dr. Cook, a member of the TWHBEA^SM Breeders' Committee, for preparing this most informative article. A doctor of veterinary medicine, Dr. Cook's Central Georgia Equine Services, Inc. in Fort Valley, Georgia specializes in equine medicine, surgery, and reproduction.
Do's and Don'ts