Nowadays, a valuable competition mare can produce offspring without interrupting its sport careerwhich is made possible by a technique called embryo transfer. The valuable mare is inseminated and anembryo is flushed seven days later. The early embryo is then transferred to the uterus of a recipient marethat carries the pregnancy to term.In 50% of the cases, flushing of the donor mare results in an embryo. After transfer, an average of70% of the recipient mares become pregnant. These percentages are influenced by several factors relatedto both the donor and recipient mares.