Old MacDonald's farm of cows and pigs is likely to have depended upon Land O'Lakes Purina Feed. As the largest US producer of animal feeds, the company manufactures and markets feed for both commercial dairy and beef cattle, and swine, and the "lifestyle" animal market. Commercial feed is purchased by farmers and livestock producers; by contrast, lifestyle feed is used by consumers that don't intend to sell their animals. In addition to livestock feed, the company makes milk-replacer products for young animals, premixes, supplements, and custom-mixed feeds, as well as offers farm-management advice. Land O'Lakes Purina Feed is a subsidiary of dairy co-op and the nation's top-selling brand of butter Land O'Lakes.