The Brazilian brothers who run the company, Wesley and Joesley Batista, are famous for their serial acquisitions—since 2005 they’ve bought more than a dozen companies for $14 billion in cash, stock, and debt. The spree has made JBS the biggest foreign meat company on U.S. soil, the world’s biggest producer of beef and chicken, and one of the largest pork producers. JBS has sustained this growth not merely by gobbling up rivals but by targeting relatively cheap, poorly managed companies and making them run better—a strategy that starts with bones. “We don’t dream to be big,” says Joesley. “We dream to be efficient.” …