|Macdonald, Jim - TAES-AMARILLO|
|Galyean, Mike - TEXAS TECH UNIV.|
|Brown, Mike - WEST TEXAS A&M UNIV.|
Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: July 28, 2007
Publication Date: February 1, 2009
Citation: Cole, N.A., MacDonald, J., Galyean, M., Brown, M. 2009. Interaction of grain co-products with grain processing: Associative effects and management. In: Proceedings of the Oklahoma State University Cattle Grain Processing Symposium, November 15-17, 2006, Tulsa, Oklahoma. MP-177. p. 193-205. Interpretive Summary: Corn milling byproducts are becoming important ingredients for feeding beef cattle. The predominant byproducts are distiller’s grains (DG), a byproduct of ethanol plants, and corn gluten feed, a byproduct of the corn starch/syrup industry. Most of the research on feeding these byproducts has been conducted where the plants are located – in the northern Great Plains and Corn Belt. In most of those studies the researchers used finishing diets common to that area. Today these byproducts are becoming available for use in the southern Great Plains where the diets are different (corn is generally steam flaked rather than dry rolled; supplemental fat is routinely added; feedyards tend to be larger; thus, management and storage of byproducts may differ). Recent research indicates that distiller’s grains have higher value in dry-rolled corn-based diets than in steam-flaked corn-based diets: i.e. there seems to be an interaction between grain processing method and the feeding of DG. This paper reviews 14 possible reasons for this interaction including diet digestibility, methane production, dietary protein form, incidence of subclinical acidosis, mineral excesses, and diet physical characteristics. The cause of the interaction is most probably a combination of these factors. This apparent interaction is important because it could result in modifications to management, such as grain processing or dietary roughage and fat content, that lower the cost of production and decrease adverse effects on the environment.
Technical Abstract: The vast majority of research with corn milling byproducts such as distiller’s grains (DG) and corn gluten feed (CGF) has been conducted in the northern Great Plains and Corn Belt with finishing diets common to that area. In the past few years, these byproducts have become available for use in the southern Great Plains. Feedlot diets in the northern Great Plains tend to differ from those fed in the southern Great Plains: 1) corn is generally dry rolled rather than steam flaked; 2) supplemental fat is routinely added in the southern Great Plains but not in the northern Great Plains, and 3) southern Great Plains feedyards tend to be larger than in the northern Great Plains; thus, management and storage of byproducts, especially wet byproducts, may differ. With increased availability of these byproducts in the southern Great Plains, researchers have begun to study the feeding of these byproducts in finishing diets more common to that area. Indeed, current research studies with steam–flaked corn (SFC)-based diets suggest DG have a lower feeding value dry-rolled corn (DRC)-based diets, i.e. there seems to be an interaction between grain processing method and DG. This paper reviews possible reasons for the interaction including: 1) basal diet composition, 2) potential for performance improvement, 3) diet digestibility, 4) effects on methane production, 5) effects of yeast, 6) dietary cation-anion balance, 7) dietary protein, 8)subclinical acidosis, 9) ethanol, 10) mineral excesses, and 11) dietary integrity & physical characteristics. The possible reasons for this apparent interaction between grain processing method and DG are not clear but are probably a combination of these factors. This apparent interaction is potentially significant because it could result in new economically beneficial changes in management such as modified grain processing or changes in dietary roughage and fat content. Because of the inherent variability in nutrient composition of wet DG and its high moisture content; the true feeding value of DG may be highly variable and may vary from one source or one load to another. Additional research would potentially be beneficial in determining how best to use these co-products in beef cattle finishing diets and their potential to possibly decrease grain processing and roughage costs.