Embryo transfer in small ruminants: the method of choice for health control in germplasm exchanges

Several thousands of in-vivo-derived sheep and goat embryos, as well as sig nificant numbers from deer, are transferred annually within countries and i nternationally. The technologies used for superovulation, collection and tr ansfer of such embryos are now well developed, and pregnancy rates of over 60% can be achieved. Such transfers offer a unique opportunity to safeguard the health status of the flocks and herds even when the embryos originate from countries with a radically different health status. Viral diseases whi ch have been investigated with regard to their risks of transfer by in-vivo -derived small ruminant embryos include bluetongue, border disease, pulmona ry adenomatosis, maedi/visna and caprine arthritis-encephalitis. Bacterial diseases investigated include brucellosis, campylobacteriosis, mycoplasmosi s and chlamydial abortion. Scrapie, a prion disease, has also been studied and will be discussed in another paper. Provided that the sanitary procedur es recommended in the IETS Manual (1998) Els outlined here, are strictly fo llowed, the risks of transmitting diseases are minimal. (C) 2000 Elsevier S cience B.V. All rights reserved.