Nestle SA pledged Tuesday to purchase only cage-free eggs for its U.S. food products by 2020, making it the largest packaged-food company to commit to such a switch and advancing a broader industry push toward more-humane animal-welfare policies. Nestle, the world's largest food maker by sales, unveiled a more-aggressive timeline than several rivals that recently said they would move to cage-free eggs, including General Mills Inc. Nestle said it uses 20 million pounds of eggs each year to make products such as Dreyer's ice cream, Buitoni pasta and Lean Cuisine breakfast items.