The purpose of this text as stated in the preface to our book "Swine Production in Temperate and Tropical Environments," 1974, is to provide a technical basis for successful production of pork in both temperate and tropical environments. The competitive position of pork as a food source both in the developed and developing countries has continued to be strengthened during the past 1 0 years. In this book, we update the current knowledge and technology upon which pork production is based-covering extensively the new knowledge of feeds and their nutrient values. The current growth of the world swine population is faster than that of the human population, reflecting the high demand for pork among consumers in all parts of the world. Advances in genetics, physiology, nutrition, and biotechnology have permitted continued improvements in efficiency of pork production, and prospects are bright for continued advances. The principles of modem production technology addressed in this book provide the basis for application by the swine industry in a broad range of environmental and economic settings. We have attempted to present a balanced coverage of the biological, economic, and husbandry aspects of swine production for use by college and university students, personnel in the feed and food industries, livesk extension specialists, and commercial swine producers.