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07.09.2022 10:43

BioRescue consortium announces 5 new embryos created after 10th oocyte collection in northern white rhinoceroses

Dipl. Soz. Steven Seet Wissenschaftskommunikation
Leibniz-Institut für Zoo- und Wildtierforschung (IZW) im Forschungsverbund Berlin e.V.

    Three years after starting its ambitious programme to save the northern white rhino from extinction through advanced assisted reproduction technologies, the BioRescue consortium draws a positive interim conclusion: Following the 10th event of harvesting immature egg cells (oocytes) in the northern white rhino female Fatu, the international team produced 5 additional embryos – bringing the total to 22 sired by two bulls. This nourishes the hope to eventually succeed in producing new offspring and give a keystone grazer of Central Africa a new future.

    At the same time, the consortium places the highest value on respecting the life and welfare of the individual animals involved. Regular veterinary and ethical assessments of oocyte collection procedures show that Fatu handles the procedures well and shows no signs of detrimental health effects. BioRescue is supported by the German Federal Ministry of Education and Research (BMBF).

    The 10th oocyte collection in northern white rhinos (NWR) was performed by a team of scientists and conservationists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), Ol Pejeta Conservancy, Safari Park Dvůr Králové, Kenya Wildlife Service (KWS) & Wildlife Research and Training Institute (WRTI) on July 28, 2022, at Ol Pejeta Conservancy in Kenya. The BioRescue team was able to collect 23 oocytes from Fatu, the younger of the two remaining NWR females. Oocyte collections from Najin, Fatu’s mother, were ceased in 2021 following an in-depth ethical risk assessment. The oocytes were immediately air-lifted to the Avantea laboratory in Cremona, Italy. Following maturation, 7 of the oocytes were fertilized using cryopreserved, thawed semen from the deceased NWR male Angalifu. Eventually, 5 embryos of Fatu were successfully produced and cryopreserved in liquid nitrogen.

    This collection followed on from the 9th oocyte collection held at the same location and by the same team on April 24th. Out of 16 collected oocytes, 3 embryos were produced in the Avantea laboratory, again using the semen of Angalifu. Successful results of both procedures raised the total number of NWR embryos produced to 22 – all of them from female Fatu, with half of them sired by the deceased male Suni who was born in Safari Park Dvůr Králové, Czech Republic, and the other half sired by Angalifu who lived in San Diego Zoo Safari Park, USA.

    Once the protocol to transfer the embryos to surrogate southern white rhino (SWR) female recipients is optimized, the embryos will be the foundation of a new NWR population, eventually destined to step back into their ecological role as keystone grazers in Central Africa.

    To set up suitable conditions for a successful embryo transfer, the team has been carefully following the interactions of the sterilized SWR bull Owuan, who serves as the oestrus detector, with the possible surrogate females that share an enclosure with him. Once the conditions allow it, the BioRescue team will attempt to conduct an embryo transfer – first with SWR embryos to demonstrate that the whole procedure works properly before the team uses the extremely valuable NWR embryos. The team is currently considering whether adding more SWR females to the program might increase the chance of achieving the first successful embryo transfer.


    Thomas Hildebrandt, BioRescue project leader and head of Department of Reproduction Management at Leibniz-IZW:
    “In 2019, one day before our worldwide first oocyte collection in NWR I said – tomorrow we will change the world. Today I can say, we did: The 5 new NWR embryos created in one set of procedures are a new record in our mission to save the NWR from the brink of extinction. In total, we managed to produce and cryopreserve 22 pure NWR embryos from 158 oocytes collected during 10 collections: 148 from Fatu and 10 from Nájin. Our next aim is to successfully produce viable offspring by inventing and using new scientific embryo transfer methods and techniques. The ground breaking scientific work we are establishing here will lay the groundwork for future conservation rescue initiatives.”

    Jan Stejskal, Director of International Projects at Safari Park Dvůr Králové: “Obtaining 22 northern white rhino embryos in three years is a fantastic achievement. However, we have to continue in producing NWR embryos as more embryos simply mean a higher chance to see a NWR baby born in the future. Thanks to the cooperation with the European Association of Zoos and Aquaria, we have southern white rhino embryos available for our next embryo transfer attempts. While we would love to have a NWR calf as soon as possible, it is necessary to proceed carefully and use the unique NWR embryos only after we achieved a pregnancy with the more easily accessible SWR embryos.”

    Cesare Galli, Director of Avantea: “The new results and the continuous successes of the previous series of collections show that we have developed a remarkably reliable process from the harvesting of the oocytes via transport to maturation, fertilization, embryo culture and freezing. Following these routines, we can expect a similar number of oocytes harvested and embryos produced in the upcoming three years.”

    Frank Göritz, Head veterinarian of the Leibniz-IZW, and Stephen Ngulu, Head veterinarian of the Ol Pejeta Conservancy: “During the oocyte collections, we closely monitor all vital parameters of Fatu and examine her reproductive tract for any detrimental effects of our procedures. Fatu shows no signs of reproductive fatigue and keeps responding well to both the anaesthesia and the hormonal protocol. Following the recent oocyte collection, Fatu was up and immediately walking after the anaesthesia was reversed and started grazing normally a few hours later like always.”

    Susanne Holtze, Scientist at the Leibniz-IZW: “The new results are also reassuring and promising in a different way. We see absolutely no signs of detrimental health effects of repeated oocyte collections in Fatu. The outcomes of the procedures are constant, but the last collection with 23 oocytes has been the most successful in terms of numbers of harvested oocytes that our team ever conducted in northern white rhinos.”

    Barbara de Mori, Director of the Ethics Laboratory for Veterinary Medicine, Conservation and Animal Welfare at the University of Padua: “Keeping a careful watch of the welfare of the animals involved and balancing these aspects with conservation benefits is crucially important to our mission. Similar to our decision to retire Najin from the programme – owing to a misbalance of welfare risks and conservation benefits – we are very certain that for Fatu the combination of highly valuable outcome for the conservation of the species and low risks of adverse health effects for her as an individual animal justify the continuation of the oocyte collections.”

    Dr. Patrick Omondi, Director/CEO, Wildlife Research & Training Institute: “We are delighted with the milestones of the project to date. The project demonstrates the success of multi-institutional and multi-disciplinary partnerships and collaborations in saving this iconic species from extinction. The collection of 23 oocytes during the 10th cycle of oocytes collection and production of five (5) pure northern white rhino embryos from them demonstrates the continued optimisation of the field and laboratory procedures.”

    Brig. (Rtd) J.M. Waweru, Director General Kenya Wildlife Service (KWS), “We are delighted as the State Agency in Kenya mandated with the conservation and management of wildlife and its habitats and as partners in the BioRescue consortium to celebrate the achievements made in recovery efforts of the Northern White Rhino’s with 22 embryos developed so far. We shall continue to give the required leadership and support to ensure the recovery efforts succeed and to look forward to the 1st northern white rhino calf being born on the Kenyan soil after a long period of uncertainty to revive the hopes of saving the species from imminent extinction”.

    Media Package

    A collection of photographs can be accessed through the following link:

    The photographs shall only be used for the news segment of media work and in direct connection with the story depicted in this press release and credit must be “Ol Pejeta / BioRescue.


    Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW)
    The Leibniz-IZW is an internationally renowned German research institute of the Forschungsverbund Berlin e.V. and a member of the Leibniz Association. Our mission is to examine evolutionary adaptations of wildlife to global change and develop new concepts and measures for the conservation of biodiversity. To achieve this, our scientists use their broad interdisciplinary expertise from biology and veterinary medicine to conduct fundamental and applied research – from molecular to landscape level – in close dialogue with the public and stakeholders. Additionally, we are committed to unique and high-quality services for the scientific community.

    Safari Park Dvůr Králové
    Safari Park Dvůr Králové is a safari park in the Czech Republic. It’s one of the best rhino breeders outside of Africa and the only place where the northern white rhino bred in human care - both remaining females, Najin and Fatu, were born here. Safari Park Dvůr Králové coordinates efforts to save the northern white rhinos.

    Kenya Wildlife Service
    Kenya Wildlife Service is the principal government institution that conserves and manages wildlife for Kenyans and the world. It also enforces related laws and regulations.

    Ol Pejeta Conservancy
    Ol Pejeta Conservancy is the largest black rhino sanctuary in east Africa, and is the only place in Kenya to see chimpanzees. It is also home to the last two northern white rhinos on the planet. Ol Pejeta’s cutting-edge wildlife security includes a specialised K-9 unit, motion sensor cameras along its solar-powered electric fence, and a dedicated Rhino Protection Unit.

    Avantea is a laboratory of advanced technologies for biotechnology research and animal reproduction based in Cremona, Italy. Avantea has over twenty years of experience and the know-how in assisted reproduction of livestock developed through years of research conducted in the biomedical and animal reproduction fields.

    University of Padua
    University of Padua in Italy is one of the oldest in the world, celebrating 800 years. Its Department of Comparative Biomedicine and Food Science is developing leading research and education in the field of wildlife conservation and welfare with a special focus on ethical assessment and evaluation of research projects and educational programmes.

    Wildlife Research and Training Institute
    The Wildlife Research and Training Institute is a state corporation established under the Wildlife Conservation and Management Act No. 47 of 2013 to undertake and coordinate wildlife research and training through innovative approaches to enable provision of accurate and reliable data and information to inform policy formulation and decision making.


    Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW)
    Thomas Hildebrandt
    BioRescue project head and head of Department of Reproduction Management
    Phone: +49305168440
    Frank Göritz
    Head veterinarian of the Leibniz-IZW and scientist at the Department of Reproduction Management
    Phone: +49305168444
    Steven Seet
    Head of Science Communication
    Phone: +491778572673
    Jan Zwilling
    Science Communication
    Phone: +49305168121

    Cesare Galli
    Phone: +39 / 0372437242 or +39 335 6240261

    University of Padua
    Barbara de Mori
    Director of the Ethics Laboratory for Veterinary Medicine, Conservation and Animal Welfare, Department of Comparative Biomedicine and Food Science
    Phone: +39-3403747666

    Safari Park Dvůr Králové
    Jan Stejskal
    Director of Communication and International Projects
    Phone: +420608009072

    Ol Pejeta Conservancy
    Samuel Mutisya
    Head of Conservation
    Phone: +254 / 720 828 231
    Roxanne Mungai
    Deputy Fundraising & Communications Manager
    Phone: + 254 / 706475737

    Kenya Wildlife Service (KWS)
    Brig. (Rtd) J.M. Waweru
    Director General
    Tel: +254 (20) 2379407

    Wildlife Research and Training Institute (WRTI)
    David Ndeereh
    Ag. Deputy Director, Research
    Phone: +254 722 556 380

    Wissenschaftliche Ansprechpartner:

    Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW)
    Thomas Hildebrandt
    BioRescue project head and head of Department of Reproduction Management
    Phone: +49305168440


    BioRescue 10th OPU_Northern White Rhino Fatu left and Southern White Rhino Tauwo to the right _ after procedure
    BioRescue 10th OPU_Northern White Rhino Fatu left and Southern White Rhino Tauwo to the right _ afte ...
    Jan Zwilling
    Jan Zwilling

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    Biologie, Medizin, Meer / Klima, Philosophie / Ethik, Politik
    Forschungs- / Wissenstransfer, Forschungsergebnisse


    BioRescue 10th OPU_Northern White Rhino Fatu left and Southern White Rhino Tauwo to the right _ after procedure

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