Birth of a foal following insemination with frozen-thawed epididymal sperm and simultaneous intrauterine delivery of homologous seminal plasma

Cryopreservation of epididymal sperm allows final preservation of the gene reserve from valuable sires in case of unexpected injury terminating the breeding career. This case report describes the birth of a healthy foal following insemination with frozen-thawed epididymal sperm. The testes and epididymides were removed under general anaesthesia and sent cooled to the laboratory overnight. The cauda epididymidis was dissected and 17.79 x 10 (9) sperm were harvested by a retrograde flush technique. A fertile mare was inseminated 1 year later with frozen-thawed epididymal sperm. Sperm were deposited into the tip of the uterine horn ipsilateral to the ovulation site. The mare did not become pregnant after the 1st cycle. In the 2nd breeding cycle, additional homologous seminal plasma was delivered into the uterus at the time of insemination and the mare was diagnosed as pregnant 14 days post ovulation. A healthy colt was born after 334 days of gestation. The method for preparing gonads for transportation to an appropriate laboratory is described for veterinarians and the different steps of semen collection and preservation are presented.