OOCYTE TRANSFER IN MARES

Oocytes were collected from dominant preovulatory follicles of donor m ares 24 hours after administration of human chorionic gonadotropin. Oo cytes were incubated in vitro for 12 or 18 hours before transfer to re cipient mares, representing maturation times after human chorionic gon adotropin administration of 36 and 42 hours, respectively. Pregnancy r ates after transfer were 4 of 5 in the 36-hour group and 2 of 3 in the 42-hour group. The overall pregnancy rate achieved (6/8 mares) indica ted that oocyte transfer may be useful clinically.