Oocytes/ICSI
Some mares are unable to produce foals with standard breeding methods and embryo transfer. Although embryo transfer can be a useful reproductive tool to treat many types of infertility, a mare must be able to support fertilization and early embryo development to be a successful embryo donor. Mares with abnormal ovulation, blocked oviducts, chronic recurrent uterine infections, severe cervical abnormalities, or other conditions that create an unhealthy environment for an embryo may be unsuccessful embryo donors but may be good candidates for oocyte recovery and subsequent fertilization.
For this procedure an oocyte (egg) is collected from the donor mare’s follicle prior to ovulation and cultured until it is mature. The egg is then fertilized in the laboratory by ICSI (Intracytoplasmic Sperm Injection). In this procedure, a single sperm cell is selected and micro-injected into the matured egg.
Once the egg divides, usually within 24 hours following fertilization, it is transferred surgically into the oviduct of the recipient mare. Since only a single sperm cell is selected and injected, ICSI can utilize very small quantities of frozen semen.
