The rendering industry likes to call itself the world's oldest recycling system. Nearly 100 percent of processed pigs will eventually get used — as meat and in uses as varied as medicine and pet food. iStockphoto hide caption

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Michael Yezzi raises 1,000 pigs a year in Shushan, N.Y. He's worried about how to keep his farm safe from a disease that has no proven cure. Abbie Fentress Swanson for NPR hide caption

toggle caption Abbie Fentress Swanson for NPR