Bovine Veterinarian - 8/13/2010 Conventional Beef Is Sustainable Beef   Beef animals from conventional feedlots that use growth-enhancing technologies and grain-based rations are three times more land-efficient than grass-fed or organic animals, an Iowa State University study found. An analysis using data from 2007 also indicated that discontinuing the use of growth-enhancing technologies would lead to an 18% reduction in U.S. beef production.   Read more:                                              • The world population is estimated to reach 9 billion by the middle of the 21st century.• The global demand for food will double by 2050 and there will continue to be increased per-capita demand for beef and other high-quality animal protein.• Worldwide, we have a limited land area on which to produce food, feed and fiber.• It is critical that we continue to conserve natural and biodiverse natural habitats.