The number of cattle and calves on feed for the slaughter market in Colorado feedlots with a capacity of 1,000 head or larger was estimated at 1,100,000 head as of May 1, 2011. This latest inventory is up 1 percent from last month and up 17 percent from last year. Cattle feeders with 1,000 head or larger capacity marketed an estimated 150,000 head of fed cattle during April 2011. This was 21 percent below March 2011 marketings of 190,000 head, but 3 percent above a year ago. An estimated 165,000 cattle and calves were placed on feed during April, 23 percent below a month ago and 3 percent below April 2010 placements of 170,000. Of the number placed in April, 21 percent weighed less than 600 pounds, 18 percent weighed from 600 to 699 pounds, 27 percent weighed from 700 to 799 pounds, and 33 percent weighed 800 pounds and greater. Other disappearance for April, at 5,000 head, is unchanged from last month but 10,000 head below last year.