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Effect of distillers grains on average daily gain of cattle grazing corn residue
There is significant potential for grazing corn residues due to the acres of corn planted annually. Grazing residues increases the length of the grazing season, allowing producers to feed less harvested feeds thereby reducing annual feed costs. The objective of this trial was to compare two types of distillers grains (DGS) at three levels of supplementation for calves grazing irrigated or non-irrigated corn residue. One hundred twenty crossbred steers were backgrounded on corn residue from November to the end of December 2012 at the University of Nebraska- Lincoln Agricultural Research and Development Center near Mead, Neb. Treatments were arranged in a 2 x 2 x 3 factorial design, with two types of DGS (modified and dried), two types of corn residue (irrigated and non-irrigated) and three levels of inclusion (0.3%, 0.7% and 1.1% body weight). Stocking rate was calculated based on grain yield of the field at harvest, grazing efficiency factor (100% for non-irrigated, 85% for irrigated) and number of hectares available for grazing. Steers were randomly assigned to treatment. Each type of DGS was fed daily through the Calan System. Diet samples were collected four times throughout the trial and were analyzed for in-vitro organic matter disappearance (IVOMD). Daily gain improved quadratically for calves supplemented at 0.3, 0.7 and 1.1% of body weight at an average of 0.77, 0.92 and 0.96 kg/day (P < 0.0001). Some feed refusals were found for steers receiving the highest levels of supplementation. Steers grazing non-irrigated residue gained an average of 0.92 kg/day in comparison to steers grazing irrigated residue at 0.80 kg/day (P = 0.0002). The IVOMD calculation showed a decline in quality of the diet samples throughout the grazing period. Steers grazing irrigated or non-irrigated corn residue while receiving supplementation at 0.7% BW show optimal performance with minimum feed refusals.
Keywords:
corn residue, grazing, stocker cattle