Effect of Corn Processing in Finishing Diets Containing Wet Distillers Grains on Feedlot Performance and Carcass Characteristics of Finishing Steers1

Three-hundred sixty calf-fed steers (BW = 318 ± 15 kg) were used in a completely randomized design to evaluate corn processing methods in finishing diets containing wet distillers grains plus solubles (WDGS). Whole corn (WC) was compared with corn processed by different methods, consisting of dry-rolled corn (DRC), high-moisture corn (HMC), a 1:1 DRC:HMC combination (DM basis), steam-flaked corn (SFC), and finely-ground corn (FGC). The SFC with a flake density of 0.33 kg/L was obtained from a commercial feedlot. Basal dietary ingredients consisted of ground alfalfa hay (5.6% of DM) and dry supplement (3.0% of DM), with the balance being WDGS (30% of DM) and corn (61.4% of DM). Final BW and ADG were greater (P < 0.05) for the cattle fed DRC (1.84 kg/d) compared with cattle fed FGC (1.53 kg/d), SFC (1.63 kg/d), and WC (1.75 kg/d), but was not different (P = 0.11) from cattle fed DRC:HMC (1.78 kg/d). Cattle fed HMC (0.185) had greater (P < 0.05) G:F compared with cattle fed FGC (0.166), SFC (0.176), and WC (0.166). No differences (P > 0.30) were detected between cattle fed HMC and DRC:HMC for ADG and G:F; however, cattle fed DRC tended to have greater (P = 0.08) ADG, yet lower (P = 0.08) G:F than cattle fed HMC. Carcass characteristics reflected performance. These data indicate that steam flaked and finely ground corn processing methods, or no processing, are not as effective as high-moisture or dry-rolled corn processing methods in finishing diets containing 30% WDGS.