EMBRYO TRANSFER

Embryo transfer is an increasingly popular method of breeding. It involves impregnating your mare (donor mare) with a stallion of your choice with either fresh, chilled or frozen semen. After 7 to 8 days, depending on the method of insemination, the very young embryo is flushed from your donor mare and transferred into the uterus of a reproductively competent recipient mare who will then carry the foal to term and raise to weaning. 

Our experienced trainers offer riding lessons for all levels and disciplines. Whether you're a beginner or an advanced rider, we can help you + The greatest advantage is that your competition mare can continue with her performance career without being held up carrying and raising a foal

+ It can allow more than one pregnancy from a mare in a breeding season

+ It can allow you to collect an embryo from a mare being bred late in the season to then be bred early the following season

+ Young mares of 2 and 3 years of age can produce offspring 

+ Mares with sub-fertility or those that cannot carry embryos themselves (past 15 days) can also produce offspring

+ It provides the opportunity to obtain foals from mares with non-reproductive health problems such as arthritis or extremely foal proud mares

+ Embryo cryopreservation (freezing of the embryo)achieve your riding goals.

The first step is to perform a reproductive soundness examination on your mare and identify where she is in her cycle. Regular ultrasound examinations of your donor mare’s uterus and ovaries is required to determine the most ideal time for insemination. When there is a dominant follicle that reaches >35mm in size then she will receive appropriate reproductive medications to program her for ovulation. Your donor mare will then be inseminated with either fresh, chilled or frozen semen of your choice using the process appropriate to the particular insemination method.

Throughout the process with your donor mare, we continually scan our herd of recipient mares to synchronise with your mare. Once their cycles are established the use of reproductive medications are administered to our recipient mares with the aim of them ovulating within 0 to 3 days after your donor mare. Ultrasound scans are continued to establish the precise ovulation times of each recipient. We arrange for multiple mares to be synchronised to each donor mare so that if an embryo is retrieved, then we are able to choose the best recipient mare to transfer the embryo into. 

7 days (fresh/chilled AI) and 8 days (frozen AI) post ovulation our vets will then perform a uterine flush on your donor mare using a specialised sterile process with specific fluid medium and filtration system to catch the young microscopic embryo. This can be a lengthy process as your donor mare is flushed multiple times consecutively to increase the chance of retrieving an embryo. The last flush is completed ultrasound guided and an injection of oxytocin is given to contract the uterus and ensure all the fluid is retrieved that might have the embryo in. On completion your mare is given an injection of prostaglandin to encourage her to come back into oestrus and therefore reduce the risk of infection from the procedure. She is then ready to go home.

The fluid that is retrieved is then examined thoroughly under a microscope and if an embryo is detected it is then “washed” into clean embryo medium, assessed and graded. The embryo is then loaded into a straw in order to inseminate/transfer into our best recipient.

The 3 recipient mares are then scanned to assess their uterine oedema, tone +/- presence of fluid. The best recipient is selected to transfer the embryo into based on this scan and their ovulation date. Once transferred the recipient receives medications to give the best chance of a successful transfer. 

The recipient mare is scanned at 12 days (5 days after transfer), again at 16 days (9 days after transfer), 28 days (21 days after transfer) and 45 days (38 days after transfer). If a positive pregnancy remains at 45 days then you may then take our recipient mare home on lease to foal and raise your foal to weaning. The result is a genetic offspring from your donor mare and stallion.

Yes, embryos can be chilled and transported. This is often done when you do all of your breeding with a local vet and they flush an embryo/s. This service has to have been pre-arranged with us prior to the flush. It is then chilled and stored appropriately to transport to our facility, ideally the same day. On arrival, we will then transfer the embryo into one of our recipient mares that has been synchronised with your mare. Close communication between all parties involved is paramount for this to be successful. 

Embryos that are recovered can be frozen. They are processed and stored using liquid nitrogen and frozen indefinitely. They can then be thawed and transferred at a later date into a recipient mare. This is an excellent way to preserve genetics however success rates of a positive pregnancy decrease after each manipulation of the embryo (recovery/freezing/thawing/transfer) as opposed to fresh embryos. 

The overall success rate of the whole process is around 35%. This incorporates the donor conception rate, recovery rate, transfer rate and pregnancy failure rate. It is therefore advised that you budget for 3 flushes and hence why our package allows for 3 flushes. There are many factors that influence this entire process which may include but is not limited to the age and fertility of the donor mare, the semen quality and insemination method, day of the embryo flush post ovulation, ovulation date of the recipient and transfer date post flush. 

In order to increase chances we recommend using a young, fertile/proven donor mare with fresh/chilled semen. Once the embryo is retrieved, it is transferred the same day with minimal handling. 

We provide embryo transfer packages which are a cost effective way to limit the total expenses incurred when facing a broad range of successful embryo recovery rates. The packages include up to 3 attempts to achieve 1 successful 45 day positive pregnancy and the lease of the recipient mare to carry, birth and raise the foal to weaning. You may also opt to be billed per service which is available also. See brochure below for prices and contract for terms and conditions. 

We are happy to scan and see if your recipient is close to/already synchronised to your donor mare. If she isn’t then it is advised to use one of our recipient mares. This is because it can take a long time to synchronise an individual mare to another, including many scans for BOTH mares (which may need to be on different days), the use of reproductive medicines on BOTH mares to manipulate their cycles together instead of just manipulating our recipients to accommodate your donor mare. The cost of the vet work to your recipient will be individually charged so it is hard to estimate how much this will cost depending on where they are in their cycle. We also like to synchronise a minimum of 3 of our recipient mares to each donor mare so that we have a choice of the best recipient at the time of transfer to give the most successful outcome. Factors such as ovulation day in comparison to the donor and uterus tone/oedema/fluid all affect the decision. Therefore only having 1 recipient does hold the risk if she doesn’t ovulate when she’s meant to or looks poor on the scan on the day of transfer there will be a risk of failure to the transfer.