A study of nonsurgical embryo transfer in the mare

The success rate of nonsurgical embryo recovery was influenced neither by year nor by season within years. The preferred method of nonsurgical embryo transfer was by Cassou pistolette. From a total of 15 attempts to transfer embryos nonsurgically, 9 (60%) were successful. Of the five attempts during February through April 1982, only one was successful in producing a live foal. The degree of synchrony between the ovulations of the donors and recipients in these five attempts ranged from +3 to −3 d. The recipient of the successful transfer ovulated on the same day as the donor. Eight of the ten attempts during September through December 1982 produced live foals. Synchronization of ovulations between the donors and recipients in these transfers ranged from 0 to −2 d. Repeated attempts to recover embryos had no deleterious effects on fertility of the donors.