Global outbreaks of bird flu in poultry have altered the flow of U.S. chicken meat, eggs and grain around the world, adding to challenges faced by domestic exporters and giving a leg up to Brazil, which has so far escaped the disease. Different strains of avian flu have been detected across Asia, Europe, Africa and in the United States in recent months, leading to the culling of millions of birds and a flurry of import restrictions on eggs and chicken meat.U.S. grain traders such as Bunge Ltd and Cargill Inc have lost business because poultry deaths have reduced feed demand. Some domestic poultry producers, though, have managed to boost sales by taking advantage of trading bans that hurt rivals.Sanderson Farms Inc, the third-largest U.S. poultry producer, said it sold more chicken to Iraq when Baghdad backed away from Europe's poultry due to bird flu