Summary and Implications
The objective of this study was to feed beef cattle to market weight (or as near as possible) by grazing coolseason grass supplemented with self-fed by-product pellets. The study took place at two locations in southwest Iowa. Yearling cattle were used at the Armstrong Farm and fall born calves were used at the Neely-Kinyon Farm. At each location, the cattle were allotted by weight to treatments of: 1) grazing with immediate access to by-product pellets in a self-feeder (early) and 2) grazing with later access (midJune) to the same pellets (late). The trial started April 21, 2005. The by-product pellets were a blend of DDGS, soy hulls, and wheat midds.
Overall, the calves supplemented the by-product feed early grew faster than the calves supplemented later. The early supplemented calves consumed 15.5 lb/day of byproduct feed and gained 2.50 lb/day. The later supplemented calves consumed 17.4 lb/day of feed and gained 2.17 lb/day overall and 2.37 lb/day while supplemented.
Overall, the yearling steers supplemented the byproduct feed early grew faster (ADG=2.61) than the steers supplemented later (ADG=1.80). The early supplemented steers consumed an average of 19.9 lb/day for 180 days. The late supplemented steers during the first period (without supplementation) gained only 0.53 lb/day, which was the result of a shortage of forage and the forage that was available was fescue. Once supplementation occurred, the late supplemented steers partially compensated by consuming 20.1 lb/day of supplemental feed and gaining 2.32 lb/day. Some of the cattle reached market weight by the end of grazing season on October 12, 2005. Five calves were harvested with an average live weight of 1,009 lb, an average carcass weight of 598 lb, and 59.3% yield. Nineteen yearling steers were harvested with average live weight of 1,225 lb, an average carcass weight of 744 lbs, and 60.7% dressing percentage. Average daily feed cost for the byproduct feed including feeder rent ranged from $1.19/day to $1.48/day.
Some lessons can be derived from this study. The byproduct feed was a ration that the cattle consumed readily from self-feeders with minimal problems. The by-product feed should be offered as soon as the cattle are put in pasture for maximal gains. With good grass, yearling steers can be expected to gain 400 to 500 lb over six months of grazing with by-product feed supplementation. Achieving choice grade may be challenging with this system.
Iowa State University
Honeyman, Mark S.; Russell, James R.; Morrical, Daniel G.; Maxwell, Dallas L.; Busby, W. Darrell; and Sellers, Joe
"Finishing Beef Cattle on Grass Supplemented with Self-fed By-Products,"
Animal Industry Report:
AS 652, ASL R2067.
Available at: http://lib.dr.iastate.edu/ans_air/vol652/iss1/13