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 10 years. In t his book we update the current knowledge and technology upon which pork production is based--covering extensively the new knowledge of feeds and their nutrient value.