Propagation of improved breeds: the role of artificial insemination and embryo transfer.

Artificial insemination (AI) and embryo transfer (ET) are not just reproductive techniques, but indispensable tools for genetic improvement. In this sense, they play an effective part in propagating improved breeds. Analysis of the development of insemination of French cattle breeds since 1960 shows how breeders can alter their genetic choices to meet economic needs. AI and ET also have their place in selection programmes: evaluating bulls by progeny testing, exerting greater selection pressure on the dams of bulls, and shortening the generation interval of breeding animals. Finally, the income of breeders is closely linked to the genetic level of the livestock which they utilise.