Multiple Ovulation Embryo Transfer (MOET) is the process whereby hormones, primarily Follicle Stimulating Hormone (FSH) are used to stimulate the ovaries of cycling cattle to induce multiple ovulations. Donors are then inseminated (often with two straws of semen) and fertilisation of the multiple oocytes occurs within the reproductive tract. Seven days later, embryos are flushed from the uterus and are either transferred as fresh embryos or frozen to be transferred at a later stage. The resulting pregnancy rates using MOET technology are expected in the region of 50% or greater. At this point of time the utilization of sexed semen using MOET technology is not efficient.

The MOET donor program process is illustrated in Donor Program Flowchart (MOET)









In Vitro Fertilisation (IVF) has a number of advantages over all other forms of assisted reproductive technologies. Oocytes are collected via ultrasound-guided aspiration of ovarian follicles, without the necessity of using potentially damaging hormones. These oocytes are then matured and fertilized in the laboratory. IVF technology allows excellent utilisation of semen. Usually one straw of semen is sufficient to fertilize all the oocytes from 10 donors. Sexed semen can be successfully used in IVF to produce 90% females. The resulting embryos are then cultured for a further seven days and fresh embryos are transferred into suitably synchronized recipients. Pregnancy rates are highly dependent on recipients. However, average pregnancy rates of 45% or better are achievable. The IVF Donor Process Map is outlined below.


As hormones are not necessary for IVF, the procedure can be repeated every two weeks, allowing the production of up to 50 calves per year. The collection of oocytes can occur from donors 10-12 months old and can be performed in donors up to four months of pregnancy.

Embryo production using IVF technology is efficient and similar to MOET. The number of embryos produced by a donor is highly dependent on the number and quality of oocytes produced. As a high degree of variability of oocytes production exists, donor ovarian function should be evaluated using ultrasonography. To ensure the very best production outcomes, this strategy is a highly recommended selection criteria in identifying donor cattle. Pregnancy rates from cryopreserved IVF embryos remains poor and variable. Recent innovation in this area, particularly vitrification and HHP technology promises to be commercially available in the near future.

International standards for IVF embryo production results in 35 transferrable embryos produced from every 100 oocytes collected. With the implementation of cutting edge human IVF techniques, ART is able to achieve embryo production rates approaching 55-60%.





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