The Use of Distillers Grains Co-Products in Feedlot Diets in the U.S. and Canada

Abstract

Continued expansion of the ethanol industry in the United States and Canada will have a direct impact in two distinct areas of beef production. First, ethanol production is an important end user of traditional feedstuffs used in beef production (corn, sorghum, wheat), and second, increased production of ethanol will result in an increase in the supply of ethanol co-products. The majority of ethanol plant expansions appear to be dry milling plants, due primarily to their relative simplicity when compared with the wet milling process. The dry milling co-product, referred to as distillers grains (DG), can be fed wet (WDGS; 35 to 50% DM) or dry (DDGS; >88% DM) with or without solubles. Based on the current process of ethanol production from corn grain, all non-starch nutrients are concentrated 300% in distillers grains compared with the original corn grain. Important nutrients to consider in feedlot diet formulation include protein, ether extract (EE), phosphorus (P) and sulfur (S). These nutrient considerations can be grouped into three main categories of interest, which include environmental (protein and P), sulfur toxicity (S) and supplemental fat (EE). Environmental concerns can be mitigated with a sound nutrient management plan. Sulfur levels in DGS should be monitored as they are likely variable and can be quite high. Corn, sorghum and wheat DGS should contain approximately 12.18, 9.09 and 7.02% fat, respectively, suggesting corn DGS will be of greater value in feedlot diets when DG are fed as an energy source compared with either sorghum or wheat DGS. Other than the type of DGS that is being fed, current information regarding feedlot performance suggests the optimum level of DGS is finishing diets is affected by inclusion level of the DG product, grain processing, roughage level, and perhaps inclusion of ionophores and antibiotics.