The optimum age for breeding a mare is between 4 and 16 years old. Ideally she has had a proven breeding history with no major "hitches" with breeding, pregnancy or foaling. She should be in good general health and condition, regularly wormed and vaccinated. While there are options to provide special treatments for problem mares, these can add to the veterinary costs of achieving and maintaining pregnancy.

Artificial Insemination

What is involved with the artificial insemination process?
Success in an AI programme is affected by many contributing factors and the timing of insemination in relation to ovulation is a major component of this success. Insemination must take place close to ovulation. This requires frequent monitoring of your mare´s reproductive tract by rectal ultrasound examination to ensure that insemination occurs at exactly the right time. Therefore, ideally, your mare should be left at the veterinary hospital during the breeding process.

If your mare has recently foaled we recommend that she undergo a preliminary examination during foal heat (8-10 days after foaling), in order to identify any post foaling complications with the reproductive tract. With early identification and treatment of problems, she may be ready to inseminate at her next cycle.

When ready for the agreed A.I. process, wet and dry mares should be brought into the clinic when coming into season (either naturally or induced by prostaglandin injection). At this time a pre-breeding evaluation will include rectal palpation, ultrasound examination of ovaries and uterus, vaginal and cervical examinations and, if necessary, collection of samples for uterine cytology, culture or histopathology.  Our vets will also get a detailed history of mare’s previous breeding performance and problems.

What you can do to maximise the success of your AI program.

In order to obtain optimum results, firstly select mares that have good reproduction history – young mares from 4 years old, and less than about 16 years have the best chances of success. Mares that are poor breeders tend to take more inseminations to achieve pregnancy and have less chance of maintaining the pregnancy to term. When choosing your stallion, make enquiries about his previous statistics for 1st cycle pregnancy and seasonal pregnancy rates when using his chilled or frozen semen.

There are of course management procedures we can incorporate to assist poor breeders to have foals, but it is just more difficult when also using frozen semen.

Information for Frozen Semen A.I. Clients

You need to be aware that the pregnancy rates from A.I. with frozen semen tend on average to be lower than with natural cover or insemination with fresh chilled semen. Best results using frozen semen are achieved if the semen is inseminated precisely at the time of ovulation although a period from 12 hours before, until 6 hours after ovulation can still be successful. Achieving this precision involves a combination of the administration of drugs that improve the predictability of ovulation, teasing and frequent ultrasound examinations (as often as every 2-3 hours) as ovulation approaches. We will do these checks through the night if necessary. We will also examine the mare after insemination to ensure normal ovulation has occurred and to check for any uterine inflammation that may need immediate and continuing treatment. We normally like mares to remain at the hospital for 3-5 days. Semen storage is available should any doses of semen remain once the mare is pregnant.

Lifespan of frozen semen:

Once thawed, equine sperm may only survive for a relatively short period – even under ideal conditions as sperm is affected during the preservation process affecting its longevity. Insemination must be timed very closely to the time of the mare"s ovulation.

Stallion fertility:

Some stored semen may be sub-fertile. We recommend that, prior to purchasing the semen for your mare, you make enquiries to ensure that satisfactory results have previously been achieved with the stallion´s frozen semen.

Mare reproductive health:

Selecting the right mare to use for AI is also important.  An ideal candidate for AI would be a young mare with a successful breeding history (including no failed attempts to become pregnant).

Chilled semen is a preferable alternative to frozen semen, particularly for stallions that are held in facilities where semen can be transported to its destination within 24hrs. Chilled semen often results in better fertility than inseminations with frozen semen, as the chilling process damages the semen less than the freezing process. Chilled semen when diluted and extended properly can survive up to 48hrs, so semen can be transported within this time easily anywhere within Australia. While the sooner chilled semen is inseminated the better, the timing of insemination is not as critical as with frozen semen. Mare owners are requested to make the initial contact with the stallion owners but we will contact the stallion owners to co-ordinate the final transport details.