Oocyte Collection

1. OPU (Ovum Pick-Up)

In a healthy mare, oocytes are collected via transvaginal follicular aspiration. This minimally invasive procedure retrieves immature oocytes directly from ovarian follicles. OPU can be performed year-round and does not require hormonal stimulation.

2. Post-Mortem Recovery

If a mare dies unexpectedly or is scheduled for euthanasia, viable oocytes can often still be recovered from the ovaries. These oocytes can be used for ICSI, allowing valuable genetics to be preserved even in emergency circumstance

Embryo Culture

1. In Vitro Maturation (IVM)

   After collection, oocytes mature in culture for 24–30 hours.
   Approximately 70% reach full maturation.

2. Intracytoplasmic Sperm Injection (ICSI)

   Semen is thawed and processed to isolate motile sperm.

   One sperm is injected into each mature oocyte.

   Enables fertilisation with low-quality or rare semen

   3. In Vitro Culture (IVC)

   Embryos are grown to the blastocyst stage (7-10 days). They are then frozen or selected for fresh transfer

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Advantages

1.Year-Round Availability

OPU can be done at any stage of the mare’s cycle, including winter anoestrus. This allows embryo production outside the traditional breeding season.

2.No Hormonal Preparation

Mares do not require hormonal stimulation.
This is especially beneficial for performance mares, which can remain in full training.

3.Ideal for Competition Mares

Genetically valuable mares can continue their sport careers while still producing foals.

4.Use Embryos at the Optimal Time

ICSI embryos are frozen and thawed only when a suitable recipient mare is available—no need for synchronisation.

5.Option to Use Your Own Recipient Mare

Because timing is flexible, owners can supply their own suitable recipient mare, reducing cost and improving control.

6.Long-Term Embryo Storage

Frozen embryos can be stored for years and transferred when conditions are optimal.

7.Suitable for Sub-Fertile or Older Mares

Even mares unable to carry a pregnancy or those producing few embryos via flushing often still produce viable oocytes for ICSI.

8.Post-Mortem Oocyte Recovery

Genetic material can be saved even after sudden death or planned euthanasia.

9.Efficient Use of Limited or Valuable Semen

Only one sperm cell is required per oocyte.
A single straw of semen may be used for multiple ICSI procedures (often up to ten).