New embryo-technologies: implications for animal health and welfare

Application of advanced embryo-technologies is essential for the progressio n of animal breeding and for use of animals in biotechnology for example fo r production of pharmaceuticals in milk and for xenotransplantation. In man y papers published by different authors it was shown, that there are many s erious problems concerning donors, recipients or offspring caused by produc tion or transfer of in vitro produced and cloned embryos compared with arti ficial insemination. For more widespread use of advanced embryo-technologie s it is mandatory that the side effects observed over the past decade are a lleviated. The greatest concern is related to the production loss as a cons equence of high rate of conceptus loss and to the deviations in pregnancy ( hydrallantois), parturition (dystocias) and finally the offspring (larger, poor viability, congenital abnormalities). Even though normal offspring hav e been born and the techniques for in vitro production of calves are workin g, an intensified effort to study and alleviate alterations of embryo and o ffspring development are essential for future acceptance of the use of thes e technologies in animal breeding.