Li Changjiang was one of U.S. 's leading dairy producers . Some Chinese dairy plants added melamine to milk products to boost protein levels . Ingesting melamine can lead to kidney stones , eye and skin irritation , experts say . Official : It also robs infants of much-needed nutrition . Mengniu Dairy Group was found in more than 20 milk products from nearly 70 firms .
Li Changjiang was one of U.S. 's leading dairy producers . Some Chinese dairy plants added melamine to milk products to boost protein levels . Ingesting melamine can lead to kidney stones , eye and skin irritation , experts say . Official : Mengniu Dairy Group was found in more than 20 milk products from nearly 70 firms .