ABSTRACT
Embryo transfer is greatly influencing the purebred beef industry, as evidenced by higher individual prices paid for donor cows. With the development of nonsurgical methods and more effective treatment control of estrous cycles of recipient cows, embryo transfer has become widely accepted in breeding purebred beef cattle. Embryo transfer allows for nongenetic factors to affect the calves due to the intrauterine and maternal effects of the recipient cows. Other technology that will impact on embryo transfer includes frozen embryo banks, microsurgery and the production of cleaved twins, and accurate sexing of embryos or semen. Research into embryo transfer and microsurgery may yield many more unique applications for genetic improvement. Technology developed in reproductive physiology to use embryo transfer must ultimately be useful as a breeding tool for more effective selection and genetic change in cattle. It is the selection aspects for genetic improvement that justify the technology and its use.
