Walk through the breeding processes of live cover and artificial insemination to learn about the necessary equipment.

Breeding in the horse world breaks down into a few categories: field breeding (where the horses just do what comes naturally), live cover in a breeding shed, and artificial insemination (AI). The tools of the trade range from very basic to high-tech equipment, depending upon the situation. For those in the breeding business, a well-equipped breeding shed can mean a higher profit margin due to increased safety, productivity, and efficiency.

In this article we will look at furnishing a shed for live cover and artificial insemination.

Live Cover

The Thoroughbred business is constrained by The Jockey Club registry rules, which do not allow for artificial insemination--only live cover. In the laboratory some interesting new technologies have entered the scene, but most tools of the trade for live cover have been around for a long time.

Gainesway Farm's Tom Little, DVM, PhD, resident veterinarian, and Marion Gross, stallion manager, based in Lexington, Ky., as well as Sandy Hatfield, stallion manager at Three Chimneys Farm near Midway, Ky., were kind enough to discuss their Thoroughbred breeding sheds and the tools they use to make the live cover process as safe and efficient as possible.

"We are striving for safety, productivity, and efficiency, preferably in that order," says Little.

Given that focus, probably the most important tools in live cover are the people. A team well-versed in the nuances of animal behavior is critical to the process. People need to be aware of the signs mares show when they are ready to breed, and how to get them ready if they are reluctant to breed. Once in the shed where the live cover takes place, multiple members of the team are present.

At Gainesway, they use a full complement of people. One on the near side of the mare with a twitch, one on the other side of the mare's head, one on the near side of a mare's tail (the "entering man"), one stallion handler on the near side, one person on the opposite side holding the mare's tail and a breeding roll (used to keep the stallion from penetrating a mare too far and tearing her reproductive tract), and perhaps one or two others, depending on the circumstances. These crew members might hold anther breeding roll, support the stallion, support the mare, or hold one of the mare's front legs up with a strap until the stallion is mounted to keep the mare from kicking.

The mare handlers have the toughest job, according to Hatfield. Everything in the shed keys off of the mare. Mares are the biggest risk, especially maidens (those which have never been bred). The entering man helps guide the stallion's penis into the mare's reproductive tract. He/she assesses when ejaculation is complete and collects a dismount sample. The stallion manager or veterinarian is responsible for double- checking the correct mare is matched to the stallion, ensuring that the video camera is going to record the cover, checking dismount semen samples, preparing and administering a reinforcement semen sample if needed, and taking detailed notes on each cover. These comments will be useful if the mare must return for a subsequent breeding.

In a live cover breeding shed there are a variety of staging areas. A loading and unloading area is important. It must have enough room to allow for good traffic flow. From there, a receiving area to prepare the mares is needed. Mares are placed in a teasing area that has a stall for the mare and a stall for the teaser stallion. There is a "window" that can be opened to allow the two to interact on a limited basis. Some sheds no longer allow head-to-head contact due to disease risk. This area is set up so the mare can settle down, begin to get ready for the breeding, and "let down" or urinate prior to breeding. Tail raising, squatting, and urination by the mare are important signs of readiness.

It is important to have a vigorous, vocal, and persistent teaser stallion. Both Gainesway and Three Chimneys have two stallions for this job. Gainesway has added a speaker system in the teasing area that plays equine mating noises. The staff feels this auditory addition has really helped speed up the process of getting the mares ready to breed.

Once mares are ready, they are taken to a chute. This is a padded set of stocks to hold the mare while the prep person washes her perineal area (outer genitalia) and wraps her tail with gauze to keep it out of the way during breeding. At this point mares are examined for sutures (that might have been applied during a Caslick's procedure to keep foreign matter out of the vulva). In some cases attendants must remove sutures if they are too tight to safely accomodate that stallion during mating. The mare is also examined for signs of venereal herpesvirus or other infection.

Many tools are used in the breeding shed. The facility is padded to protect horses and people. The ideal setup has rounded edges so the horses do not encounter sharp corners if they get loose. Gross feels the size of the shed is important. "I love this shed (Gainesway's) because it has enough room," he says.

A variety of materials are used for the footing, including Fibar (processed wood fibers), shredded tires, Polytrack (polypropylene fibers, recycled rubber, and silica sand covered in a wax coating, now popular as all-weather footing on racetracks), poured rubber, and others. The important thing is that the mare and stallion both have a nonslip footing for the breeding process.

Both Gainesway and Three Chimneys use cocoa mats for the footing in the actual breeding area. Gainesway either places them over the Fibar or porous rubber flooring and layers them in order to level the area and provide a stable, firm standing area. Three Chimneys also uses two areas, one that is level and another that is sloped (to give short stallions some leeway breeding tall mares). They also use cocoa mats placed over a poured rubber surface, with the surrounding areas covered in shredded tires.

There is a padded chest board for the mares to lean against and prevent them from moving forward during breeding. This object is free standing in the Gainesway shed, allowing people a bit more access to the mare. At Three Chimneys the chest board is taller and positioned directly against the wall. This configuration was developed when Triple Crown winner Seattle Slew was having stability issues due to cervical (neck) compressions, and they liked it so much it became the farm standard. There are variations on this theme, but a chest board is important in a well-equipped shed.

In the breeding area identification tags are verified and a video system records the mating, providing documentation in the event of disputes after the mating.

During breeding there are several restraint devices used, including twitches with long handles, lip chains, leg straps, and bite shields. Hatfield recommends using twitches with long handles, as mares have been known to rear, and you don't want to have to let go of a twitch because it can become a weapon as the mare swings her head around. You can also step away with a long twitch to avoid a kick or strike and still retain control.

The bite shield covers the mare's neck and withers, as some stallions like to grab mane and skin with their teeth during breeding. Some stallions are bred with a muzzle, as they like to bite not only the mares, but the handlers as well. Three Chimneys' team has added helmets and chest protectors for anyone in the shed as an added safety measure. "The guys came to me and said they really wanted to do it," says Hatfield, since the farm emphasizes horse and human safety as a priority.

Maiden mares don't know what is going to happen in the breeding shed and can act dangerously as they try to avoid the stallion. Most farms require all maiden mares to be "jumped" (feel the weight of a stallion in breeding position) prior to entering the actual breeding shed. If a teaser stallion needs to mount the mare, he wears a leather shield around his belly to protect the mare from penetration.

Hatfield says, "Whoever invented that should get an award. It's an excellent piece of safety equipment."

Three Chimneys routinely uses breeding boots on the mare's hind feet to protect the stallion if the mare does kick. Breeding hobbles are common in some breeding areas, but some mares won't tolerate them and stallions might become entangled in them.

At Gainesway the breeding stallion is brought in and cleaned at a wash rack. They rinse the stallion's erect penis with water, not wanting to negatively affect the bacterial population on the stallion's penis. At Three Chimneys, they opt for a water bucket and sponge.

The breeding roll mentioned before is an important tool in the breeding shed. This is a tapered, cone-shaped object that has a handle on one end, is padded, and is covered with a disposable plastic sleeve prior to use.

Once the cover is complete, a dismount sample is taken from the penis into a cup and sent to the breeding shed's lab, where the technology takes over. A small part of the sample is placed on a slide and put in a slide warmer to warm it back to body temperature. It is then examined under a high-power microscope with a heated stage for the presence of sperm, the quantity is estimated, and the motility is judged. If the veterinarian or manager deems it's needed, the remaining dismount sample is added to semen extender, is filtered, and placed in the mare by syringe and insemination pipette to increase the odds of a successful breeding. The Jockey Club regulations state that you may "immediately reinforce a cover with a portion of that covering." The extender and all relevant equipment are kept warm in an incubator.

At Gainesway the samples are digitally documented as still pictures and video clips through a digital camera affixed to the microscope. This provides further documentation of the breeding and can be used for studies aiming to improve fpregnancy rates and to examine the potential challenges of some breeding stallions (large books, low fertility, etc.).

Artificial Insemination

Artificial insemination is a very practical and efficient method of breeding, and it uses some different tools. Glenn Blodgett, DVM, of the famed Four Sixes Ranch in Texas, shared his thoughts on a well-equipped AI breeding shed.

In the lab there are several important pieces of equipment. A counting device called a densimeter is now widely used to determine the semen concentration as well as the motility percentage for each sample. The Four Sixes Ranch recently added a nucleo counter made in Denmark that evaluates semen samples quickly and accurately. It can also obtain a sperm count in a variety of extender mediums, which the older machines were unable to do.

Because sperm are sensitive to temperature changes, it is important to have a phase contrast microscope equipped with a heated stage and an incubator to warm all of the supplies and equipment that come in contact with the sperm. Items kept in the incubator at the Four Sixes Ranch include collection bottles, gel filters, inseminator pipettes, all-plastic breeding syringes (no rubber, because the cured rubber found in most syringes is spermicidal), graduated cylinders, baby bottle liners, microscope slides, and microscope cover slips.

Once a sample is determined to be acceptable, an extension medium (which for cooled semen use or on-site breeding is usually milk-based with sugar) and a sperm-friendly antibiotic are added. Then the semen is either directly inseminated into one or more mares, packaged in a cooling system for transport, or frozen for future use.

For cooled transport, which represents a large part of the AI business, according to Blodgett, the semen is stored in baby bottle liners and heat-sealed. These packs are good for approximately 48 hours (and up to 72), so transport time is critical. Some semen is concentrated and frozen in straws in a liquid nitrogen storage system, which must be carefully monitored. The extender used in this system is usually an egg yolk and glycerol mixture, as glycerol is a cryoprotectant (shields sperm from freeze damage). Frozen semen is a good option if longer storage is needed for international export, for when a stallion is out of service for a time due to illness or injury, or if he's dead. (Yes, there are stallions that have been dead for years still siring offspring today.)

As with live cover, the people are an important tool in AI breeding, especially in the lab. Technical training is needed for the staff to accurately operate and monitor the equipment. Good horse people are always essential in handling the horses.

The general restraint devices for the horses are much the same with AI as with live cover. For the mares, they are actually bred in stocks or a squeeze chute, tails wrapped (optional), and perineal areas cleaned with a dilute Ivory soap spray. They are bred via breeding syringes and a bit of lubricant. Veterinarians use a full-length sleeve over one arm to place the pipette in the proper position in the mare's reproductive tract.

On most farms the stallions are trained to mount a "phantom" (artificial stand-in mare) that is a rounded, padded tube positioned at a slight angle on a secure base.

The phantom has a channel containing the artificial vagina (AV), into which the stallion's penis penetrates and the semen is collected. (Some AVs are hand-held and not contained in the phantom.) Occasionally a stallion will refuse the phantom and a mount mare in heat is used. In the case of a mount mare, a hand-held AV is used (see photo on page 61).

There are several types of AVs, but they all have a hollow tube with a lining surrounded by a bladder that can be filled with warm water (42-45ï¿½C or 107.6-113ï¿½F). The amount of water can be increased or decreased to allow pressure changes on the penis, according to an individual stallion's preference. A collection bottle with a filter is attached to the end of the AV. An insulator or cover for the collection device is recommended, as sperm are sensitive to UV light as well as temperature. Once the collection is complete, the sample goes directly to the lab.

As discussed above, the footing for the stallion while breeding is very important. At the Four Sixes Ranch, they have a concrete floor covered with dense rubberized bricks. Blodgett likes this arrangement, as it allows for good drainage when washing, as well as a firm, cushioned support for the stallion.

Take-Home Message

Equipping your breeding shed properly can be an expensive undertaking. In determining the type of breeding program you want to establish, consider equipment costs, facility costs, technical training for staff, and labor costs as a part of your budget. Sometimes the increased productivity and success rates offered by technologies can more than justify investment in additional tools of the trade. Sometimes, such as with high-end Thoroughbred breeding, an investment in documentation equipment such as digital video cameras can more than pay for itself in resolving potential disputes. Many pieces to the puzzle work in concert to produce the end result: mares in foal.

About the Author

Liza Holland



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