Embryo transfer in cattle

Abstract

The topic of embryo transfer in cattle has received a great deal of publicity in all major cattle-producing countries in the world. This has come about, as has often happened in science, by a fortunate combination of major economic changes in the cattle industry, causing increased demand and higher prices for valuable livestock, and by improvements in the state of the art, especially the reports from Rowson and his colleagues (16-19) of high fertility after transfer of either one or two fertilized eggs to suitable recipients. Cattle ovumtransfer teams have sprung up in many countries and include veterinarians operating out of private clinics, as well as commercial enterprises devoted to techniques of improving cattle production. Substantial numbers of transfers have been performed commercially in Canada and Britain but have not yet been fully reported. Limited numbers of transfers have been reported from research laboratories in Japan, France, Canada and the United States (4,8,20,23-27). There is widespread interest by organizations associated with artificial insemination; however, before the commercial use of the technique of embryo transfer can be considered a success, it seems obvious that many problems have to be overcome. It is the purpose of this presentation to assess the present position and, particularly, to draw attention to the gaps in knowledge which are evident in this field. It is not my purpose to be unduly cautious; on the contrary, I believe the technique will find an important place in increasing efficiency of cattle production.