Effects of Increasing Levels of Distillers Dried Grains on Forage Intake and Digestibility of Moderate Quality Fescue Hay

The purpose of this study was to determine the differences in voluntary intake and digestibility of moderate-quality, long-stem fescue hay (9.5% crude protein (CP); dry matter (DM) basis) by steers consuming 4 levels of distillers dried grains with solubles (DDGS) (27.7% CP; DM basis). Four ruminally cannulated Hereford steers (avg 364 +- 63 kg initial body weight (BW)) were housed in individual pens (4 x 4 m) and randomly assigned to treatment blocks in a completely randomized, replicated 4x4 Latin Square experimental design. Treatments were Control (C), Low (L), Moderate (M) and High (H) and were fed at 0, 0.2, 0.4, and 0.8% of BW daily, respectively. Each period consisted of a 10 day adaptation and a 7 day collection, during which hay intake, orts, and total fecal output were measured daily, followed by a 10 day washout. Data were analyzed using GLM Procedure of SAS, where the model included the fixed effects of treatment and period and steer was included as a random variable. Total dry matter intake increased (P = 0.02) and total organic matter intake increased (P = 0.003) as DDGS supplementation increased. Total tract, apparent organic matter digestibility increased (P = 0.01) as DDGS supplementation increased. Total NDF and ADF intake and digestibility was not different (P ≥ 0.19) between treatments. When fed at 0.4% of BW or greater, DDGS supplementation decreases voluntary intake of moderate-quality, long-stem fescue hay