02/03/2024
Over the past couple of years, the term “”ICSI”” has become a more common technology being used as an option for both mare and stallion owners in equine reproduction, but what exactly is ICSI and why has it become so popular?
ICSI stands for Intracytoplasmic S***m Injection—which in basic terms is the process of injecting a SINGLE s***m cell into the oocyte (egg) to fertilize it. This technology originated as a way to OPTIMIZE the success potential of both stallions and mares who may encounter reproductive challenges in one way or another (subfertility, limited semen quantity, etc).
In the case of a stallion having limited semen quantity availabe, ICSI is beneficial in that it utilizes a MUCH small number of s***m cells. This is done by cutting and thawing a small piece of a single frozen semen straw or by sending in a much smaller dose of fresh or cooled semen.
On the mare side, oocytes can be harvested through a process called “”aspiration”” anytime over the course of the year (vs. having to wait until breeding season for the mare to cycle) or even from ovaries that have been removed from a mare post euthanasia. Once oocytes are harvested and matured, the ICSI process begins.
A “Micromanipulator” is the specialized microscope used to inject the single s***m cell into the oocyte. This process is done by holding the oocyte in place with suction from a rounded glass pipet while the s***m cell is injected through the zona pellucida (exterior cells of the oocyte) and into the cytoplasm of the oocyte (or the center of the egg).
From there, highly trained and specialized lab technicians—known as Embryologists—monitor the now fertilized embryo for cell growth and development until it becomes a viable embryo for cryopreservation (freezing) or to be transferred into a recipient—a process that takes approximately 7-10 days.
