In a groundbreaking achievement, the BioRescue consortium has successfully achieved the world’s first pregnancy of a rhinoceros through embryo transfer. The southern white rhino embryo was created in vitro using collected egg cells and sperm, and then transferred into a southern white rhino surrogate mother at the Ol Pejeta Conservancy in Kenya on September 24, 2023. After 70 days, the BioRescue team confirmed the pregnancy, with a healthy 6.4 cm long male embryo. This milestone paves the way for the transfer of northern white rhino embryos, a critical step in the mission to save the species from extinction.
On the same day, the BioRescue scientists and veterinarians, in collaboration with the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), performed the historic embryo transfer at the Ol Pejeta Conservancy in Kenya. The embryos, created using oocytes from Elenore at Pairi Daiza Zoo in Belgium and sperm from Athos at Zoo Salzburg in Hellbrunn, Austria, were fertilized in vitro at Avantea’s laboratories in Cremona, Italy, before the transfer. Two embryos were transferred to increase the chances of success.
This achievement comes after 13 previous embryo transfers, a testament to the pioneering work of the BioRescue team. With only two northern white rhinos remaining in the world, the stakes couldn’t be higher. The conservation science program has already produced and cryopreserved 30 northern white rhino embryos, a crucial step in the race against time to save the species from extinction.
The successful transfer of a southern white rhino embryo is just the beginning. The next step, transferring a northern white rhino embryo, is uncharted territory and required the development of new protocols, methods, and equipment. Ethical considerations are also paramount, with all procedures subjected to rigorous ethical assessments.