In the near future, improvement of domestic animals for the production of food and fiber is poised to undergo a revolution by the utilization of recent breakthroughs and advances in molecular genetics, embryo manipulations, and gene transfer systems. Utilization of these techniques will have a wide impact on animal agriculture by improvement of production efficiency via manipulation and control of many physiological systems. The end result will be to decrease production costs, increase food production and quality, and lower food costs. Health and well being of domestic and other animals will be improved as a result of new methods of disease diagnosis, vaccine production, and disease prevention practices. Genetic engineering also offers the possibility of utilizing animals for the development of pharmaceutical products to benefit society. Research progress will be enhanced via manipulation of the gene pool.