ICSI

Oocyte Aspiration / ICSI Coordination

Weatherford Equine provides comprehensive oocyte aspiration services for mares undergoing intracytoplasmic sperm injection (ICSI). Our veterinarians have extensive experience with immature follicular aspiration, pre-ovulatory aspiration, and post-mortem oocyte recovery, allowing us to tailor the approach to the individual mare and breeding program.

Donor mares may be managed in-house at Weatherford Equine or presented on a haul-in basis for scheduled aspiration. We also work closely with referring veterinarians who prefer to manage donor mares locally, coordinating timing and treatment so mares can be shipped to Weatherford specifically for the aspiration procedure.

Recovered oocytes are prepared and shipped to the ICSI laboratory selected for the case. Weatherford Equine has longstanding relationships with established ICSI laboratories and routinely coordinates cases with multiple facilities, while remaining flexible to the preferences of the mare owner and referring veterinarian.

Our involvement does not have to end with oocyte shipment. Our reproduction team can also assist with semen coordination, communication with the ICSI laboratory, embryo return, recipient mare selection and management, and embryo transfer, providing continuity throughout the breeding process.

Whether a mare is managed entirely through Weatherford Equine or in partnership with a referring veterinarian, our goal is to make the ICSI process as efficient and coordinated as possible while allowing each breeding program the flexibility to choose the laboratory and management approach that best fits its needs.

EXPERIENCE THAT MATTERS

Thousands of oocyte aspiration procedures performed
Experience with immature, pre-ovulatory, combination, and post-mortem oocyte recovery
Donor mare management available in-house or on a haul-in basis
Established working relationships with leading ICSI laboratories
Coordination from aspiration through embryo return and transfer

Reasons to Pursue ICSI

Stallions with limited availability of semen* or stallions with low quality semen

Mares that are no longer able to produce embryos via traditional methods

Unexpected death of a mare

Overview of the Process for Utilizing ICSI

The first step of the ICSI procedure is to recover oocytes from the mare. The oocytes are recovered by transvaginal follicular aspiration (TVA). In this procedure, using ultrasound guidance, a needle is used to aspirate follicles present on the ovary. The procedure is performed with the mare standing in the stocks under sedation and takes 15-60 minutes depending on how many follicles are being aspirated. This can be done as an outpatient procedure.

ICSI procedure (injection of a sperm cell into an oocyte)

Once the oocytes have been collected they are carefully processed, packaged and sent to a reputable equine ICSI lab for fertilization.

The next step occurs at the ICSI lab and requires a small amount of semen that can be fresh or frozen depending on availability. This is when the actual ICSI takes place. ICSI stands for Intra-Cytoplasmic Sperm Injection and is performed by injecting a single sperm cell directly into the mares oocyte. The fertilized egg is then cultured in the lab until it becomes a transferable embryo.

Once a healthy embryo has been cultured at the laboratory (process takes 7-10 days) the resulting embryos will need to be implanted into recipient mares. We work closely with the ICSI labs to coordinate shipping them back to Weatherford Equine for transfer, or to the recipient facility of your choice. If ICSI is performed in the off season, or if excess embryos develop, the embryos can be vitrified and the shipping is coordinated at a later time.

Aspiration Options

Mature oocyte

Immature oocytes

Pre-Ovulatory (Mature) Aspiration

A dominant pre-ovulatory follicle is aspirated shortly before ovulation.
This approach allows the oocyte to mature naturally within the mare.
Typically only one dominant follicle is available per cycle.
This approach requires appropriate cycle timing and a cycling mare.

Immature Aspiration

Multiple follicles are aspirated during a single session.
Recovered oocytes undergo maturation at the ICSI laboratory prior to fertilization.
This approach can provide multiple oocytes from a single aspiration and does not require a dominant pre-ovulatory follicle.
The number of follicles and recovered oocytes varies considerably between mares.

Combination Aspiration

Combines aspiration of a pre-ovulatory follicle with aspiration of the remaining immature follicles during the same procedure.
May be considered for mares with a relatively low follicle count when the goal is to maximize the opportunity to produce embryos from a single aspiration session.
Because mature and immature oocytes are typically injected on different days, separate ICSI injection fees may apply depending on the laboratory.