Want your mare in Texas bred to a stallion residing in Germany? It’s easy with today's equipment and technology.

Today's equine planned parenthood means that humans intervene, sometimes using veterinary equipment that helps them get the job done effectively. In this article we'll take a look at the modern tools you might use for breeding, whether you operate a prolific stallion station or have a small facility of your own.

Diagnostic Equipment

An ultrasound unit is an important piece of equipment for any efficient breeding operation. Ultrasonography involves the use of high-frequency sound to produce a two-dimensional picture of soft tissue. It works by pulsing a sound beam and using the returning echo to create a picture.

Practitioners are not bound to large machines; today they can choose more advanced digital equipment and software that can change a laptop into an ultrasound viewing device. Veterinarians use the machines to determine the best time for insemination by watching follicle development in the ovaries.

"We usually use a 5.0 megahertz probe, inserted rectally, to look down on the reproductive tract," says Fernando Cardenas, DVM, from 3H Veterinary Services in New Hill, N.C. "What we are doing is staging the follicle. We start on Day 2 or Day 3 of estrus and keep coming back to the farm to follow that follicle to ovulation. Staging the follicle is important because timing is the key for breeding (especially for artificial insemination). You need to give the stallion owner enough advance notice to get the semen ready for next-day delivery. If you are using frozen semen, you need to ultrasound the mare every six hours. Frozen semen is less viable so you need to get (the semen deposited) as close to ovulation as you can."

Artificial Insemination Equipment

Although live cover is fairly straightforward and has its own specific tools, artificial insemination (AI) requires a wider range of equipment on the stallion's side.

The artificial vagina (AV) is the most common tool used for collecting stallion semen for AI. It is a tubular, hand-held canister with a latex liner. A water jacket surrounds the liner, which can be filled with warm water to simulate the mare's vagina. There is a collection apparatus on one end, usually including a filter to keep out the gel part of the ejaculate. Once the stallion mounts the mare or dummy, the stallion's penis is diverted into the AV and semen is collected.

There are several makes and models of AVs to choose from, and you can make a decision based on the AV's lightness, ease of use, and stallion preference.

Busy facilities employing AI generally use stocks, as they help keep the mare still and straight, making it safer for the person performing the artificial insemination. The stocks are usually made of metal pipe, and they are equipped with a padded kickboard at mid-gaskin level to protect the veterinarian or handler at the back (and prevent self-injury). The stocks are set in concrete with nonslip mats underfoot. Stocks can also be fashioned by placing the mare in her stall with her hindquarters positioned in the doorway and hay bales at her hocks to protect the handlers.

A phantom or dummy can take the mare out of the semen collection equation. It's possible to train stallions to associate the dummy--a rounded, sturdy, padded "body," held up by a single post and covered in a non-rip material--with breeding. The height, angle, and width should simulate a mare's body, approximately 5½ to 6 feet in circumference. The phantom mare must be big enough that the stallion can balance himself on it.

Many breeding sheds lead in an in-heat mare to arouse the stallion before diverting him to the dummy.

After collection, someone uses a microscope to look at semen samples or dismount samples to ensure the stallion's ejaculate contains viable sperm.

Another useful device is the pH meter, an electronic instrument used in this case to measure the acidity or alkalinity of semen. Stallion semen pH should be 7. A higher pH can indicate contamination from urine or other substances or problems with the sex glands.

Large breeding facilities often use a hemocytometer, a device originally created to count blood cells, but which is now used to count other cells and microscopic particles. "For breeding purposes, the hemocytometer measures the concentration of the semen and potency and helps determine how much to dilute it prior to shipping," says Cardenas. To preserve the sperm's fertility during shipping, the semen needs to be extended to a certain ratio, such as 4-to-1 or 3-to-1, depending on the concentration of the semen.

Semen extenders can assist metabolic activity and protect the sperm against potentially damaging temperature changes. It is usually made of glucose with a skim milk base, and it often includes antibiotics. Semen extender is available as a dried mixture contained in an envelope (resembling powdered milk).

Shipping semen is possible with the use of cooling and special shipping containers. These containers lower the temperature of the semen to keep the sperm viable for 24 to 48 hours--the time it takes for next-day delivery and insemination of the mare.

The hard-shelled insulated Equitainer is generally considered to provide the most optimal cooling. The Equitainer has a lead shield to protect the contents from airport security X ray machines. The semen is shipped in the container in a bag with freezer packs, and then after it reaches its destination it is transferred into a syringe for use.

Disposable cooling and shipping systems such as Equine Semen Transporter, Equine Express, Bio-Flite, and ExpectaFoal are made from cardboard and Styrofoam. The enclosed semen is cooled with a special freezer pack. The disposable systems are inexpensive, and there is no need to return them. "The other convenience is the semen is shipped in a syringe instead of a bag," says Cardenas. "That's a little bit easier for the practitioner because it removes that extra step. The one drawback is that on hot days, the disposable containers probably do not keep the semen as cold during shipping."

Whatever the shipping method, once the semen arrives someone must pass a disposable pipette through the mare's cervix and deposit the semen into the body of the uterus.

Insemination Technology

"If a bull doesn't do what he's supposed to, he goes down the road. Not so with horses."--Dr. Pete Sheerin

In the performance-oriented world of horses, breeding animals are not always selected on the basis of fertility, so practitioners are called upon to assist in achieving a pregnancy.

"In cattle, if the bull doesn't do what he's supposed to do, he goes down the road. But not so with horses," says Pete Sheerin, DVM, Dipl. ACT, a reproduction specialist at Rood & Riddle Equine Hospital in Lexington, Ky. "We need to manage a horse by employing whatever method works for that particular animal."

This is a challenge for veterinarians and, luckily, reproductive technology and husbandry methods are constantly advancing.

Veterinarians might use hysteroscopic or deep-horn insemination, among other techniques, to get mares in foal to stallions with lower sperm numbers or reduced fertility. With methods such as this, a small sperm dose can be placed directly at the tip of the uterine horn in a mare that is ovulating, increasing the chance of pregnancy.

"We know that we can put lower sperm numbers on the uterine papillae and have acceptable pregnancy rates in fertile horses," says Sheerin. "This procedure also makes semen go further. If you have an ejaculate from a stallion that has lower sperm numbers and you only have several billion sperm, but you have a lot of mares to breed, you can use 10 to 50 million range per mare" to make the available semen stretch further.

With deep-horn insemination, the veterinarian passes a catheter through the cervix to the end of the uterus and deposits sperm near the end of the horn (on the side where the mare has ovulated).

The veterinarian can also perform hysteroscopic insemination with a video endoscope, a thin tube with a flexible camera attached, which allows him or her to view the procedure on a monitor. "In this case the uterus has to be inflated with air (so that he or she is) able to see," says Paul Morris, DVM, of Equicenter, a breeding clinic in Pilot Point, Texas, that specializes in embryo transfer. "The air is then aspirated and the catheter is passed through the endoscope to deliver the sperm."

Although many of these techniques became available around the same time, Morris says the benefit of the deep-horn insemination technique is that it requires simple equipment rather than the more costly endoscope. "With the endoscope you can see the papillae and see where you're placing the sperm, but you can put it near the same place with a catheter. It's all in the hands of the operator."

Take-Home Message

In a modern world of breeding, almost anything is possible, and if a foal with parents on separate continents is what's wanted, it's easy to achieve--with the right equipment, of course.

About the Author

Sharon Biggs Waller

Sharon Biggs Waller is a freelance writer for equine ­science and human interest publications. Her work has appeared in several publications and on several websites, and she is a classical dressage instructor.

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