Finishing performance of feedlot cattle fed condensed distillers solubles

Two experiments evaluated the effects of condensed distillers solubles (CDS) on performance and carcass characteristics of finishing beef cattle. In Exp. 1, 250 crossbred steers (initial BW = 355 ± 18 kg) were fed 0, 9, 18, 27, or 36% CDS (DM basis) which replaced a portion of urea and a 1:1 ratio of dry-rolled corn (DRC) and high-moisture corn (HMC). Steers were divided into 3 BW blocks and were assigned randomly to 25 pens. Dietary fat increased from 3.7 to 9.4% as CDS inclusion increased from 0 to 36%. Intake decreased linearly ( < 0.01) as CDS increased. A quadratic response was observed for ADG ( = 0.01) and G:F ( < 0.01) with maximum gain calculated at 20.8% CDS and maximum G:F at 32.5% CDS inclusion, which was 12% more efficient than those fed 0% CDS. Experiment 2 was designed as a 2 × 4 factorial using 400 crossbred steers (initial BW = 339 ± 15 kg) evaluating 0, 7, 14, or 21% CDS (DM basis) in 2 base byproduct diets containing either 20% modified distillers grains plus solubles (MDGS) or 20% Synergy (a blend of wet corn gluten feed and MDGS). Steers were divided into 2 BW blocks and were assigned randomly to 40 pens. A tendency for a base diet × CDS inclusion interaction was observed for ADG, HCW, and final BW ( < 0.10). Gain increased linearly ( = 0.01) and tended to increase quadratically ( = 0.09) in MDGS diets, with maximum calculated ADG at 16% CDS inclusion. Inclusion of CDS had no effect on ADG in Synergy-based diets. Increasing CDS resulted in a linear increase in G:F ( < 0.01) regardless of basal diet. Condensed distillers solubles may be included in the diet at greater than 30% (DM basis) without other byproducts and improve animal performance. Likewise, CDS can be fed in combination with other byproduct feeds but with less improvement in performance.