Cattle and calves on feed for slaughter market in the United States for feedlots with capacity of 1,000 or more head totaled 10.1 million head on July 1, 2010. The inventory was 3 percent above July 1, 2009. The inventory included 6.25 million steers and steer calves, up 4 percent from the previous year. This group accounted for 62 percent of the total inventory. Heifers and heifer calves accounted for 3.77 million head, up 1 percent from 2009.