Recent advances in reproductive technologies: implications for livestock production and animal nutrition

摘要

Scientific advances in molecular genetics and cell biology over the last decade have brought anew dimension to our understanding of the mechanisms controlling the growth and health of farm animals and the quality of animal products. Techniques are evolving that will soon allow any desired modification to be made to the mammalian genome. Future opportunities for animal production are limited only by the scientist's imagination and the ethical acceptability of such developments by national governments and the general public. Paralleling these advancements in molecular biology are developments in the reproductive technologies on which they depend. Such developments are less controversial as, in addition to facilitating genetic modification, they canalso be used to enhance reproductive rate, facilitate gender pre-selection, conserve farm animal genetic resources and accelerate genetic progress through conventional selective breeding regimens. The purpose of the present paper is to review recent developments in these technologies, and to briefly consider their application in livestock production and implications for animal nutrition. It begins with artificial insemination (AI), representing the first generation of reproductive technologies and the one that has had the greatest global impact on livestock production (20 percent of the estimated 540 million breeding cows in the world are artificially inseminated; Thibier and Wagner, 2002), and concludes with transgenesis, the technology that has the greatest potential to alter livestock production.