This project aimed to make significant improvements in technologies for the multiplication of bovine embryos by combining methods for in vitro maturation of oocytes and in vitro culture of embryos with existing nuclear transfer technology. The second main objective was to develop embryonic stem cells from cattle embryos by culture techniques and to investigate opportunities for using the nuclei of such cells for transplantation, and the generation of embryos on an extensive scale. Funding was provided by the Milk Marketing Board, the Meat and Livestock Commission and the Department of Trade and Industry. The work was carried out jointly by the Cambridge and Edinburgh Research Stations of the AFRC Institute of Animal Physiology and Genetics Research, and was based within Animal Biotechnology Cambridge Ltd. The scientific director was E.J.C. Polge.