An international team of scientists has achieved the world’s first rhinoceros pregnancy following an embryo transfer. The BioRescue team took a southern white rhino embryo produced in vitro from collected egg cells and sperm and transferred into a surrogate mother at the Ol Pejeta Conservancy in Kenya on 24 September, 2023. The team have now confirmed a pregnancy of 70 days with a well-developed 6.4 cm long male embryo. The ovarian cells used in producing the embryos were retrieved from Elenore, a southern white rhinoceros living in the Pairi Daiza Zoo in Belgium while the sperm used for fertilisation came from Zoo Salzburg’s male, Athos. The embryo was then transferred to surrogate mum Curra after she mated with a sterile bull, Ouwan. The team have now confirmed a pregnancy of 70 days with a well-developed 6.4 cm long male embryo. However, sadly surrogate mum and ‘dad’ died due to intoxication with bacteria spores unrelated to the pregnancy. Despite this, after dissection the team found the 70-day-old male foetus. The research now paves the way to conduct a similar procedure in order to save the southern white’s critically endangered relative, the northern white rhino. Only two remain in the wild, at Ol Pejeta, mum and daughter Najin and Fatu, meaning that without a similar procedure, the species likely has no future.
