The potential of embryo transfer for infectious disease control in livestock.

This review of the general epidemiological aspects of embryo transfer indicates that the transfer of embryos provides the opportunity to introduce genetic material into populations of livestock while greatly reducing the risk for transmission of infectious diseases. Studies of specific diseases of livestock confirm that many pathogens are likely to be excluded when embryos are transferred. Twenty years of commercial embryo transfer under field conditions in a variety of species has not resulted in a single documented transmission of an infectious disease agent. Strategies for insuring that embryos are free of pathogens include the use of donors that are specific pathogen-free, washing of embryos, the trypsin treatment of embryos, or a combination of these methods. Although researchers continue to develop new procedures for the treatment of embryos to provide an even greater margin of safety, it is clear that existing techniques for the handling and transfer of embryos can be used to limit the spread of infectious diseases.