Châtenay · Béligneux Breeding Center: The Stud Farm
Embryo transfer.
Historical expertise, responsible use.
Embryo transfer following insemination is a technique that the BLH and Dr. Neyrat’s teams have mastered since the 1990s. Since 2019, the bulk of our embryo work has focused on the implantation of frozen embryos derived from ICSI. Fresh embryo transfer remains, however, a viable option for certain mares, who are housed at the Châtenay Center from March through August.
A technique that remains relevant
Choose the right tool for the mare, not the other way around.
The development of OPU and ICSI has profoundly changed reproductive strategies. However, this does not render fresh embryo transfer obsolete. For some mares, artificial insemination followed by embryo collection remains a simple, consistent, and cost-effective approach.
Our role is to evaluate the donor’s profile, the intended semen , her reproductive history, and the breeding objective in order to guide the owner toward the most appropriate method. Fresh embryo transfer is therefore not recommended as a matter of course: it is selected only when it truly aligns with the breeding plan.
The Course at the Châtenay Center
From the donor’s arrival to confirmation of pregnancy.
Fresh embryo transfer relies on a process that is simple in principle— —but demanding in execution: monitoring the donor— —synchronizing the recipient— —embryo retrieval— —must all be carried out in precise sequence.
Preparing for the Mare's Arrival
Upon arrival at the center, the donor mare is provided with all the necessary items for her care: up-to-date health records, vaccination against equine rhinopneumonitis, boarding agreement, and documents related to the breeding program.
The goal: to have a complete, legible, and usable “ ” file available to the veterinary team from day one.
Track Your Cycle and Sync
Our veterinarians monitor the donor mare’s ovarian function un , insemination, and ovulation. At the same time, a recipient mare with a compatible cycle is identified and monitored to ensure the best possible synchronization between the two mares.
The quality of this synchronization directly affects the rest of the journey .
Retrieving and Preparing the Embryo
About 7 to 8 days after ovulation, the donor’s uterus is flushed with saline solution. The collected fluid is then filtered and examined by our technician to locate the embryo.
Once identified, the embryo is evaluated, washed, and prepared immediately before implantation.
Transfer to the receiver
The synchronized recipient is prepared for embryo transfer. The veterinary e t places the embryo in her uterus, and then the team provides gynecological monitoring of the pregnancy .
An early examination is performed around 12 days, and follow-up continues until pregnancy is confirmed at 45 days.
Confirm the pregnancy and make plans for what comes next
Once pregnancy is confirmed at 45 days, the surrogate mare can be transferred to the breeder under our lease agreement and remain there until the foal is weaned.
From that point on, ensuring the continuity of care and the well-being of the receiving becomes a shared responsibility between BLH and its tenant .
In 2027, BLH will no longer offer stallions available for insemination at in its own catalog. However, the fresh embryo transfer service will still be available using stallions from other breeding farms.
We intend to keep this service within a deliberately targeted scope. It will be reserved primarily for our loyal clients, for mares boarded long-term at the stud, as well as for donor mares for whom ICSI has not proven sufficiently effective.
Surrogate Mares · Our Code of Ethics
A recipient is not a biological donor.
This mare has been entrusted to you.
When you use our service for renting a surrogate mare , our organization is designed to maximize the chances of success: rigorous herd management, in-depth knowledge of each individual, precise gynecological monitoring, and selection of the most suitable surrogate at the time of implantation.
This technical requirement goes hand in hand with an equally important one: respect for the mare. Mares in foster care who leave Châtenay must be housed, fed, monitored, and cared for with the same diligence and kindness as your own horses.
"This is our code of ethics regarding these mares. For the duration of the lease, it becomes yours as well."Listen to the "Receveuses" podcast
Selection, synchronization, monitoring, placement, and accountability: —BLH explains our approach to surrogacy.
Your Mare · Your Plan · The Right Technique
