Title: Effects of concentration and source of wet distiller's grains on digestibiity of steam-flaked corn-based diet fed to finishing steers Authors
|Mccuistion, Kimberly -|
|Greene, L. Wayne -|
|Mccollum, F. Ted -|
Submitted to: Professional Animal Scientist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 6, 2011
Publication Date: July 1, 2011
Citation: Cole, N.A., McCuistion, K.C., Greene, L., McCollum, F. 2011. Effects of concentration and source of wet distiller's grains on digestibiity of steam-flaked corn-based diet fed to finishing steers. Professional Animal Scientist. 27:302-311. Interpretive Summary: Today nearly 30% of the U.S. grain production is used to make grain based fuel ethanol. Currently most of the grain-based ethanol plants in the United States are located in the Northern Great Plains and Corn Belt, where most of our corn is produced. In the past few years, ethanol plants have expanded into the Southern Great Plains where grain sorghum is an important crop. A co-product of ethanol production is distiller's grains – essentially the fat, protein, fiber, and minerals remaining from the grain after most of the starch has been converted to ethanol and carbon dioxide. Research is needed to determine the optimal ways to use distiller's grain in feedlot diets fed in the Southern Great Plains, where over 30% of U.S. cattle are fed annually. To that end, we evaluated the digestibility of sorghum-based wet distiller's grains plus solubles (SDGS) and corn-based distiller's grains plus solubles (CDGS) in steam-flaked corn-based diets typical of those fed to finishing beef steers in the Southern Great Plains. Steers were fed diets containing increasing concentrations of SDGS (0, 5, 10, and 15% of dry matter) and one concentration of CDGS (10%). The distiller's grains replaced steam-flaked corn, cottonseed meal, and/or urea in a high-concentrate finishing diets. The effects of distiller's grain on apparent digestibility of dry matter, organic matter, ash, protein, phosphorus, fat, neutral detergent fiber and starch were relatively minor. The digestibilities of SDGS and CDGS were similar. Results of this study indicate that SDGS and CDGS can be fed in steam-flaked corn based diets at concentrations as high as 15% of the diet dry matter without adversely affecting diet digestibility.
Technical Abstract: The source and dietary concentration of wet distiller's grains may affect the digestibility of beef cattle finishing diets. The objectives of this experiment were to evaluate the effects of graded levels of a sorghum + corn-based wet distiller's grains plus solubles (NMDGS) and corn-based distiller's grains plus solubles (CDGS) on digestibility of steam-flaked corn-based diets fed to finishing beef steers and to determine potential effects on ammonia emission from feces and urine. Ten beef steers (average body weight = 252 kg) were used in a replicated 5 x 5 Latin square design. Steers were fed diets containing increasing concentrations of NMDGS (0, 5, 10, or 15% of dry matter: CONT, 5NMDG, 10NMDG, or 15NMDG, respectively) and one concentration of CDGS (10% of dry matter: 10CDG), which replaced steam-flaked corn, cottonseed meal, and/or urea in a high-concentrate finishing diet. Apparent digestion of dry matter (DM), organic matter (OM), ash, nitrogen (N), phosphorus (P), ether extract, and neutral detergent fiber (NDF) were quadratically affected by dietary NMDGS concentration with lowest values for the 5NMDG and 10NMDG diets and highest values for the CONT and 15NMDG diets. Digestion of DM, OM, ash, N, P, and NDF in the 10NMDG diet were not different (P > 0.10) from digestibility of the 10CDG diet. Digestibility of CDGS and NMDGS, determined by difference, were not different (P > 0.10). In vitro ammonia losses increased (P < 0.09) with an increased NMDGS in the diet. Results of this study suggest that the digestibilities of NMDGS and CDGS are similar and that, at the concentrations used in this study, wet distiller's grains with solubles have only minor effects on total-tract digestibility of diets based on steam-flaked corn.