A worker arranges slaughtered cattle in the freezing room in the Marfrig Group slaughter house in Promissao, 500 km northwest of Sao Paulo October 7, 2011. Brazil is the world?s second largest beef-exporting country by volume acording to the USDA (United States Department of Agriculture). The world's population will reach seven billion on 31 October 2011, according to projections by the United Nations, which says this global milestone presents both an opportunity and a challenge for the planet. While more people are living longer and healthier lives, says the U.N., gaps between rich and poor are widening and more people than ever are vulnerable to food insecurity and water shortages. Picture taken October 7, 2011 REUTERS/Paulo Whitaker (BRAZIL - Tags: ANIMALS FOOD EMPLOYMENT BUSINESS)