Effects of drying distillers grains plus solubles on feedlot cattle performance and nutrient digestibility

All dry milling ethanol plants produce wet distillers grains (WDG) and distillers solubles (DS). Depending on the plant, WDG and DS will be combined to produce wet distillers grains plus solubles (WDGS). Some plants will partially dry WDGS and market modified distillers grains plus solubles (MDGS), or other plants will completely dry WDGS to produce dried distillers grains plus solubles (DDGS). These products have been shown to contain greater feeding values than the corn it replaces in finishing diets. However, as drying intensity of distillers grains plus solubles (DGS) increases, the feeding value relative to corn decreases. Three finishing experiments and two metabolism experiments were conducted to evaluate the effect drying WDGS has on finishing cattle performance and carcass characteristics and the effects on nutrient digestibility. Diets containing DGS had greater ADG and were more efficient than the corn-based control. As a result, cattle fed DGS had heavier HCW and greater 12th rib fat thickness at harvest. Using the G:F values, all types of DGS regardless of moisture content had greater feeding values than the corn it replaced. Additionally, WDGS had greater feeding values than MDGS and DDGS, and MDGS had a greater feeding value than DDGS. Although not significant, diets containing WDGS had numerically greater NDF digestibility than diets containing DDGS. Organic matter digestibility was improved for WDGS compared to DDGS. Completely and partially drying WDGS reduces the feeding value in finishing diets and reduces OM digestibility.