Use of a linear ultrasonic transducer for the transvaginal aspiration and transfer of oocytes in the mare

Abstract

Summary A 5 MHz linear ultrasonic transducer was used for the transvaginal aspiration and transfer of oocytes through the use of an ultrasonically-guided needle. Mares (n=18) with a follicle ≤30 mm were given human chorionic gonadotropin (hCG); follicular aspirations were attempted between 17 to 28 hours (mean of 24 hours) later. Oocytes were recovered from 14 of 18 aspirations (78% collection rate), and intrafollicular oocyte transfers were attempted in 7 recipients. Recipients were given an injection of hCG approximately 24 hours prior to transfer of an oocyte into the follicle. Two of the 7 oocyte transfers resulted in twin conceptuses. The techniques used in this preliminary study resulted in the recovery of equine follicular oocytes and in the successful intrafollicular transfer of oocytes.