Mare Services

At Maraboon Rural Veterinary Services, we are dedicated to providing quality reproductive services for horses, ensuring optimal success for both mare and stallion owners. With our brand new purpose built facilities and experienced staff, we offer comprehensive support throughout the breeding process. Below is an overview of the core services we provide:

 

PREPARE MARE FOR LIVE COVER:
Live cover involves taking your mare to a stallion for breeding. In some cases stallions will have very full books for a breeding season and can only serve a certain number of mares each day. These stallions usually also only have time to serve a mare once rather than multiple services over a number of days. In order to maximise conception rates in these cases we can assist by scanning your mare to determine the stage of her cycle and inducing ovulation with medications to allow for live cover at an optimal time. Please note: Stallions that are standing at Maraboon Rural Vet Services are not offering live cover so we will only be offering this service to mares that are travelling to outside stallions.

 

ARTIFICIAL INSEMINATION:
The process of artificial insemination involves ultrasounding the mare’s uterus and ovaries to determine where she is in her cycle and then determining the optimal time for insemination using chilled, fresh or frozen artificial insemination.

  • Fresh Semen: Can be collected and inseminated on site, providing fresh, high quality semen.
  • Chilled semen: Can be collected anywhere in Australia or New Zealand and transported to our facility for insemination. This method provides flexibility while maintaining semen viability for up to 48 hours.
  • Frozen semen: Can be stored at our facility for use when required. This method offers long-term storage and global access to genetics, making it ideal for rare or deceased stallions. Our experienced team handles the precise timing and management needed for successful frozen semen breeding.

Advantages of Artificial Insemination:

  • More mares can be bred to the same stallion
  • Mares don’t need to travel large distances or interstate for breeding
  • Less risk of injury to mares or stallions
  • Prevention of spread of sexually transmitted diseases
  • Reduce the risk of mating associated contamination in problem mares 

Artificial Insemination Procedure:

  1. A stallion is chosen and a breeding contract is signed between the mare owner and the stallion owner/agent. The type of semen to be used is also determined – fresh, chilled or frozen.
  2. The mare is brought to our breeding facility on her first day in season or if this is unknown, any stage of her cycle.
  3. A breeding soundness assessment is conducted to examine the ovaries, uterus, cervix and vulva to determine whether there are any potential problems that could impact breeding.
  4. The mare is then scanned regularly to determine the size of the follicles on her ovaries and therefore the optimal time for insemination. Depending on the mare and her cycle this could take between 2 and 10 scans or on occasion even more.
  5. Once the follicle reaches an optimal size (between 30 and 40mm depending on the horse), an ovulation medication is administered to reliably induce ovulation 36-48hrs post injection which allows for timed insemination.
  6. Once we are getting close to our optimal size we will inform you of when to order the chilled semen (if this is what is chosen) for the best delivery time. If using frozen semen we ask that this be couriered to us prior to the first mare scan so that it is ready to go. We will examine the semen after insemination to assess the motility.
  7. After insemination the mare is usually given medications or flushed to optimise her chance of conceiving. Some problem mares are scanned after to check for accumulation of fluid and to ensure ovulation has occurred. Most mares return home 1-2 days after breeding.
  8. A pregnancy ultrasound is performed 14 days after ovulation has occurred. If pregnant, further scans at 30 and 45 days are also performed to ensure the pregnancy is still viable. If a pregnancy certificate is required this can be done at 45 days. 

 

EMBRYO TRANSFER:
Embryo transfer (ET) is a more involved process that includes transferring the embryo from one mare into another recipient mare that acts as the surrogate for that foal.  There are many reasons for choosing this route for your mare including:

  • High value mares that must remain in competition
  • Mares that can’t carry foals to term
  • Potentially have multiple offspring from the same mare
  • Can do out of season breeding
  • Reduce the generational interval in younger mares 

This is not a procedure that is recommended on all mares but can be suitable for certain situations where we otherwise wouldn’t be able to get a foal from that mare.

 

Embryo Transfer Procedure:

  1. Synchronization: The donor mare’s cycle must be closely aligned with that of one or more recipient mares. Ovulation in the recipient is closely monitored to ensure it is between 2 before and 4 days after the donor mare ovulated (ideally 1-2 days after the donor). To support this, we maintain a dedicated herd of recipient mares at our facility.

    • Recipient Mare Sale: Once a suitable recipient is selected, she is sold to the
      client and can be taken home until the foal is weaned. A buy back program is
      encouraged and appreciated, upon her return in acceptable condition (see
      below for details).
  2. Breeding the Donor Mare: The donor is monitored by ultrasound to determine the ideal breeding time and is inseminated using fresh, chilled, or frozen semen.
  3. Embryo Development and Retrieval: After successful fertilization, the embryo remains in the oviduct for about six days, then moves to the uterus. The embryo is flushed from the mare at day 7-8 of gestation. Then the embryo is washed and graded before being transferred to a recipient mare that is at the same stage of her cycle as the donor mare.
  4. Transfer and Pregnancy Check: The recovered embryo is transferred immediately to a synchronized recipient mare. Pregnancy is confirmed via ultrasound on day 14 post-ovulation.

 

If providing your own recipient mare some things must also be taken into consideration during her selection process to optimise the outcomes and the likelihood she will carry a foal to term:

  • Clinically healthy mare that has no comorbidities that could affect her reproductive performance
  • 3-15yrs of age
  • Good body condition with regular cycles and good social behaviour as she will have to be handled frequently
  • Not lactating as this can affect the mares cycles 
  • Maiden mare or one that has had 1-2 foals
  • The mare should be the same size or larger than the donor mare to minimise foaling problems 

Due to there being more steps involved in embryo transfer the chances of success are lower than for other methods of assisted reproduction. Depending on the type of insemination chosen will depend on the success of conception in the donor mare. Embryo recovery if the mare is pregnant is around 70% and then once transferred to the recipient there is an 80% chance of conception. Therefore meaning embryo transfer results in around 56% of embryos producing a live foal. If using chilled semen this equates to around 45% of cycles producing a foal. 

Due to the lower success rates this is not a procedure that is taken lightly by people and it can become a costly process if multiple cycles are required to get a pregnancy in the recipient mare. These pregnancies are also occasionally lost before they make it to term which can make it a very disappointing process. So care must be taken when choosing to have embryo transfer done in your mare. 

 

Click HERE for the 2025/2026 pricing guide

QUESTIONS AND ANSWERS:

 

What type of semen do I choose – fresh, chilled or frozen?
While stallions are usually chosen for their pedigree, conformation and performance, it is also important to consider their fertility, availability and the type of semen on offer. Some stallions are only available for live cover while others are only available for artificial insemination through chilled or frozen semen. Each option has its advantages and disadvantages and as such need to be considered closely when deciding to breed your mare. 

Fresh Semen
Fresh semen, if fertile, can last up to 7 days in a mare’s reproductive tract. Some stallion semen does not withstand the chilling or freezing process very well and therefore is only suitable for live cover or fresh semen artificial insemination. Some breed associations such as the Australian Studbook does not allow the registration of horses that are born to artificial insemination or embryo transfer. 

Natural mating also comes with risks such as injury to the stallion or mare, risk of transmission of diseases and high volumes of semen causing reaction and fluid build up in the uterus. There are some benefits in using artificial insemination such as the use of lower volumes of semen, reduced risk of injury to the mare and stallion and reduced risk of transmission of disease. Artificial insemination also have a similar conception rate to natural service with 75% for AI and 80% for natural service. 

Chilled Semen 
The process of chilling semen involves collecting the stallion then examining and extending the semen for transport. The semen is extended using a liquid that protects sperm against seminal fluid, provides nutrients, cooling buffers and antibiotics to reduce disease transmission. It is then packaged and cooled slowly in the transport container. This allows semen to be sent throughout Australia and New Zealand which increases access to stallions. Extended semen can live for up to 48hrs following processing however better quality semen can last up to 3-5d while poorer quality semen may only last 12-24hrs. 

The benefits of using chilled semen include that it can be done at home reducing the risk of travelling mares and foals, frequent ultrasound to detect abnormalities in the reproductive cycle or tract of the mare and allows for accurate timing of insemination to improve conception. It also allows for smaller volumes of semen to be used which can be beneficial for problem mares. There are increased costs to using chilled semen including stallion collection fees, semen transport fees and scanning fees involved in coordinating ovulation time. Not all stallions have semen suitable for being chilled so this must be checked prior to selecting a stallion. 

Most mares are suitable for the use of chilled semen, though older mares have lower success rates. If breeding sub-fertile or problem mares you should use the most fertile semen possible to optimise the results. 

Frozen Semen
Frozen semen is processed by adding a liquid diluent to extend the semen and ensure it will withstand the freezing and thawing process. After freezing, the semen can be stored indefinitely in liquid nitrogen (-196 degrees Celsius), and thawed just prior to insemination. Frozen semen does not last as long in the reproductive tract once thawed as chilled semen does so more scans will need to be performed to ensure insemination occurs within 6hrs of ovulation. The main advantage of frozen semen is the ability to store semen for an extended period of time, this allows access to other stallions including those overseas without being limited to what is available close to the mare. It also allows the use of semen from stallions that have died to allow their progeny to live on. 

The major disadvantage of frozen semen is the conception rate is approximately 50% of what live cover or chilled semen is which equates to about 30-40% per breeding cycle. Depending on the semen quality some stallions will achieve better or worse conception rates than this and unfortunately not all stallions are suitable for freezing. Because of this it is important to select a mare that has a good chance of getting pregnant rather than problem mares that are less likely to get in foal regardless of the quality of the semen. There is an increased cost associated with frozen semen due to the shorter survival times after the freezing and thawing process and the need to inseminate as close to ovulation as possible which requires more frequent ultrasounding. 

When choosing a mare for frozen semen it is important to consider the following:

  • Age of the mare: mares younger than 10yrs have better success rates
  • Previous breeding history: if she is a proven breeder to natural service or chilled AI she is more likely to be successful with frozen AI
  • Problem or subfertile mares are not good candidates for frozen AI