The Ovum Pick Up-ICSI procedure consists in the collection of oocytes from the donor mare followed by the fertilization of the oocytes (ICSI) and by the culture of the fertilized oocytes in laboratory incubators to grow the embryos up to the stage suitable for freezing.

The whole procedure, from oocyte collection to embryo freezing, requires 9-10 days (for example: OPU on Monday, ICSI on Wednesday, embryo freezing the following week on Wednesday-Thursday).

The OPU procedure is performed by a team of veterinarians while the donor mare is under standing sedation and low epidural anesthesia. Particular care is taken to reduce the possible discomfort of the mare by administering pain killers and anti-inflammatory medication during and after the procedure. The oocytes are collected via an endovaginal ultrasound probe equipped with a double lumen needle and connected to an aspiration pump in order to recover the follicular fluid and the oocytes that are inside the follicles.

At the time of OPU, or the day after, the mare owner must communicate to the lab the source of the semen for ICSI because Avantea does not provide semen directly but stores in his semen bank numerous straws available for ICSI and belonging to several stallion centers and private client owners.  

After collection the oocytes undergo a period of maturation followed by fertilization by direct injection of one sperm in each oocyte. This procedure requires a special microscope with high magnification objectives and equipped with a micromanipulator and a sperm micro-injector. Just a fraction of semen straw (approx. 1/10) is sufficient for ICSI of all the oocytes recovered by OPU, even if OPU is performed on several donor mares that require the same stallion for ICSI.

After ICSI and culture in laboratory incubators the embryos obtained are frozen and stored in liquid nitrogen. Before transfer the embryos must be thawed, rinsed in embryo thawing solutions and finally transferred in recipient mares 4 days after ovulation.

Expected results

  • On average 2 embryos can be obtained from each OPU-ICSI procedures carried out on Warmblood donor mares. For Arabian donor mares the average is 1 embryo.
  • The pregnancy rate after transfer of frozen-thawed ICSI embryos, in a well-managed herd of recipient mares, can be in excess of 70%.

For export to Europe, some health tests must be performed on the mare before the OPU (Coggins test valid for 90 days, CEM test (with PCR) valid for 1 year). For export to non-European countries, additional tests are required and we advise to contact our offices before planning OPU-ICSI.