Evaluation of Corn Distillers Solubles on Finishing Steer Performance

Six hundred crossbred steers (BW = 435 kg; SD = 41) were used to evaluate the effects of corn distillers solubles (CDS) on performance and carcass characteristics of finishing steers. Five treatments with 6 pens per treatment (20 steers/pen, n = 6) were used in a generalized randomized block designed experiment with three BW blocks. Treatments consisted of a control diet (CON) containing 68% dry-rolled corn, 17% high moisture corn, 10% alfalfa, and 5% supplement; CDS was included at 8, 16, or 20% of DM and replaced corn. An additional treatment combined 16% CDS with 20% wet distillers grains plus solubles (WDGS). The treatment containing 16% CDS in combination with 20% WDGS was included in order to compare WDGS to corn in diets containing CDS. Steers were limit fed for 5 d at the beginning of the trial and weighed on d 0 and 1 to account for gut fill, and were implanted on d 1 with Component TE-200. Steers were harvested at 110 d (heaviest 2 blocks) or 117 d (lightest block) and carcass data were collected. Linear and quadratic effects of increasing CDS concentration were evaluated using orthogonal contrasts and a pairwise comparison was used to compare 16% CDS with 16% CDS and 20% WDGS. Treatment x block interactions were tested, but were not significant (P > 0.08). Final BW, ADG, G:F, fat thickness, and HCW linearly increased (P < 0.01) with increasing CDS concentration, while DMI tended to increase quadratically (P = 0.06) with CDS inclusion. Feed efficiency linearly increased from 0.136 in CON to 0.140 at 8% inclusion, 0.146 at 16% inclusion, and 0.149 at 20% inclusion of CDS. When comparing 16% CDS with 16% CDS and 20% WDGS, DMI decreased (P = 0.04) and G:F tended to increase (P = 0.08) when WDGS was included in the diet. No other differences for carcass characteristics were observed (P > 0.12). The feeding value of CDS when compared to corn was calculated at 139, 146, and 147% for 8, 16, and 20% CDS inclusion levels. When 16% CDS was compared to 16% CDS in combination with 20% WDGS, a feeding value of 115% was calculated for WDGS relative to corn. With recent changes in oil removal from CDS, the feeding value appears consistent with previous work and suggests CDS has more energy than corn for finishing cattle.