This is a study of the number, capacity, and production of cooperative feed manufacturers in the U.S. formula feed industry. Cooperative mills with a capacity of 10,000 tons per year or more increased both the number of mills and total output. Number of establishments and production decreased for smaller mills. Formula feed production rose from 20 million tons in 1975 to 24 million tons in 1984. This production remained centered in the Corn Belt and Lake States regions. However, the Southeast saw the greatest increase in production by cooperatives and also the strongest market share of formula feed by cooperatives. Meal remains the most common feed form produced by cooperatives and dairy the most common livestock consumer group.