Artificial Insemination
Are you considering breeding options for your mare? For many breeds, getting your mare in foal to a local stallion is not the only option available. Artificial insemination (AI) and semen preservation techniques make it possible to ship semen anywhere in the country - and even around the world. Success of these techniques depends on the careful reproductive management of the mare and the stallion.
AI is the placement of fresh, chilled or frozen semen into mares to replace natural breeding. Chilled and frozen semen allow for transportation over longer distances, whereas fresh semen requires insemination shortly after collection.
Chilled semen involves the collection from a stallion using an artificial vagina. Following microscopic examination, the semen is ‘extended' (to prolong life), chilled, and then transported to be inseminated into the mare within 24 hours of collection. Frozen semen involves collection from a stallion, but after examination the semen is concentrated and frozen down so that it can be stored indefinitely. Frozen semen can be transported when required by the mare.
Advantages of AI
AI allows breeders to gain access to bloodlines and genetics from horses around the world, at a realistic cost, without having to worry about importation of these horses.
Traveling mares long distances to a stud can be stressful, especially if she has a foal at foot. Decreased transport costs are advantages where transported semen can be used.
It can be expensive sending a mare away to stud. Using AI in a mare means she only spends a short period of time away from home at a local breeding facility.
Limiting exposure of mares and their foals to other horses can reduce the risk of some diseases and injuries.
Older mares, that are problem breeders or prone to infection following natural service can be inseminated in an attempt to reduce infection.
Frozen semen can be collected from stallions and transported anywhere in the world, meaning semen from old or injured stallions can still be used.
Artificial insemination, however, is not without its disadvantages and therefore is not a procedure that should be undertaken without careful thought.
Disadvantages of AI
There is a large variation in ‘chilling' and ‘freezability' among individual stallions. Thirty percent of stallions produce semen that freezes well, 40% satisfactory and 30% unsatisfactory. With chilled semen around 70-80% is suitable for chilling. There is no direct correlation between natural fertility or fresh transported semen and frozen semen. The only real way to assess the success of a stallion's chilled or frozen semen, is the ability to get mares in foal.
Intensive mare management is required, involving ultrasound examination of the mare's ovaries at regular intervals to determine the best time for AI.
Conception rates with AI using frozen semen are lower than with fresh semen. With a good freezing technique, proven stallions and well managed mares, conception rates of 60-65% can be reached.
Management of the mare
Prior to AI, Totally Vets will take a full reproductive history (previous foaling history, mating history including problems conceiving etc) of your mare and perform a full reproductive examination. During the early breeding season, the mare should be kept where she can easily be ‘teased' by a stallion or gelding. Prior to placing your semen order, it is important to obtain as much information about the stallion as possible from the stud - especially his success rates with transported semen.
An initial uterine scan will be performed to determine the stage of the mare's cycle. Hormonal drugs are occasionally used to bring the mare into oestrus. Ovulation is monitored using a series of ultrasound scans. As frozen semen requires the semen to be placed inside the uterus as close to the time of ovulation as possible it requires more frequent examinations. Hormones may also be used at this stage to help predict the timing of ovulation. Once inseminated, the mare is rescanned several times (16days, 27days and 42days) to check for pregnancy.
Management of the Stallion
The stallion should be evaluated for fertility prior to the breeding season, and it is critical for a stallion's sperm viability to be checked after a dose has been extended or cooled for 24 to 36 hours.
Semen is collected from the stallion in an ‘artificial vagina' as he jumps a phantom or dummy mare. Some stallions need to jump a real, hormonally controlled mare and then be diverted to the container. The semen is then analysed for quality, motility and sperm count. This semen can then be extended and frozen or chilled.
AI cost breakdown
Each insemination is termed a ‘round'. Mares that do not conceive on the first round may, at the owner's discretion continue with further attempts on another round. As a general rule, mares not conceiving after three rounds of using the same stallion should change stallions. Costs include veterinary time, ultrasound scans and the drugs normally used to induce heat, and ovulation. Drugs used to treat post-insemination reactions are also included. Any treatments outside of this will only be undertaken following consultation.
Totally Vets (Palmerston North) can agist a limited number of mares for short term only, ie for the 3-5 day period of oestrus and insemination. Subsequent scans can either be done at Totally Vets or at the owners place depending on available facilities, with any travel to the owner's property being an additional charge. Dry mares for insemination with chilled semen are the preferred candidates for this option.
AI may be carried out at home, provided facilities are suitable for restraining mares that are to be rectally palpated. Rectal palpation is not without risk, and therefore requires solid facilities in the form of a crush to restrain the mare and minimize the risk of damage. A power source is also required to allow us to run the ultrasound machine. Some form of heat detection (either a good showing mare or a teasing gelding) is also required. Vet travel is charged on top of the standard AI fee. Mares where chilled semen is to be used are the preferred candidates for this option.
Totally Vets looks forward to offering you this service. If you would like more information on AI or a cost estimate for this service, please contact the experienced team at the Breeding Unit, Totally Vets Ltd, Ph 06 356 5011, Fax 06 353 6005, email admin@totallyvets.co.nz.
