On average a success rate of about 50% can be expected, but much higher figures have been obtained. The success rate of embryo transfers depends on prevailing conditions such as:

• Physical conditions of the surrogate ewes
• Stress factors
• Accuracy of preparation of the surrogate ewes
• Feeding conditions after transferring
• Health condition of ewes
• Quality of the embryos (company responsible for flushing the embryos)
• Quality of the implants (person responsible for transferring the embryos)

There is a tendency to sell 2nd grade embryos. These embryos will most certainly have an impact on the success rate. GLG prides themselves in only supplying 1st grade embryos.