Influence of Distillers Dried Grain Supplementation Frequency on Forage Digestibility and Growth Performance of Beef Cattle

Three experiments evaluated the influence of supplementation frequency of distillers dried grains plus solubles (DDGS) on forage digestibility (Exp. 1) and growth of yearling heifers (Exp. 2) and steers (Exp. 3). In Exp. 1, 6 steers (371 ± 30 kg) were used in a replicated 3 × 3 Latin square design with three 21-d periods. Treatments were DDGS fed at 16.7% of the diet (DM) either 1) daily, 2) every other day, or 3) every third day. In Exp. 2, 48 heifers (193 ± 20 kg) were fed hay and supplemented with the daily equivalent of 1.3 kg/ heifer of DDGS, either 3 or 6 d/wk. In Exp. 3, 48 steers were assigned to replicated supplementation groups. Treatments were 1) hay and supplement fed 6 d/wk in a dry lot (control); 2) native winter range and supplement fed 6 d/wk; 3) native winter range and a DDGS supplement fed 6 d/wk; and 4) native winter range and the same DDGS supplement fed 3 d/wk. In Exp. 1, diet DM (P = 0.06), OM (P = 0.07), and hay NDF (P = 0.03) digestibility decreased linearly as DDGS supplementation frequency decreased. In Exp. 2, heifers fed DDGS 6 d/wk gained more BW (P = 0.01) than heifers fed 3 d/wk. In Exp. 3, steers fed the control diet, native winter range and supplement fed 6 d/wk, and native winter range and DDGS supplement fed 6 d/wk performed similarly, but performance was decreased when steers were fed native winter range and the DDGS supplement 3 d/wk. Improved animal growth may result from more frequent supplementation of DDGS when fed in excess of 15% of the diet.