Corn or sorghum wet distillers grains with solubles in combination with steam-flaked corn: Feedlot cattle performance, carcass characteristics, and apparent total tract digestibility

Two studies were conducted to evaluate the effects of corn (CDG) and sorghum (SDG) wet distillers grains with solubles on feedlot cattle performance, carcass characteristics, and apparent total tract digestion of nutrients. In Exp. 1, 224 steers were used in a randomized complete block design (initial BW 391.1 +/- 9.51 kg) and fed steam-flaked corn (SFC)-based diets consisting of (DM basis) 0% distillers grains (CON), 15% SDG, 30% SDG, 15% CDG, 30% CDG, 15% of a 50: 50 blend of SDG and CDG, and 30% of a 50: 50 blend of CDG and SDG. Decreased carcass-adjusted final BW and HCW (P <= 0.05) were noted as the inclusion amount of distillers grains increased in the diet. Body weight gain efficiency did not differ among the CDG, 50: 50 SDG and CDG blend, and CON treatments, but G:F was numerically less with either amount of SDG than for CON, and decreased (P <= 0.05) as distillers grains were increased from 15 to 30%. Cattle fed CON had greater carcass yield grades than those fed the distillers grain diets (P <= 0.05). In Exp. 2, crossbred beef steers (n = 36; initial BW 567.3 +/- 53.1 kg) were used in a generalized randomized block design and fed SFC-based diets with 0% distillers grains (CON) and 15% (DM basis) CDG or SDG. Digestibility was determined with a pulse dose of Cr2O3. Feeding steers 15% CDG or SDG increased intakes of CP and NDF (P <= 0.05), but intakes of DM, OM, and starch did not differ among treatments (P >= 0.07). Apparent total tract digestibilities of DM, OM, CP, NDF, and starch (P >= 0.25) did not differ among the 3 treatments. Fecal pH averaged over all sampling times was not affected by treatment, nor were average fecal pH values for prefeeding samples (0, 24, 48, and 72 h after the pulse dose) or for samples taken after feeding (12, 36, and 60 h after the pulse dose; P >= 0.11). Results suggest that with 15% distillers grains in the DM, G: F was similar for cattle fed the CDG, 50: 50 SDG and CDG blend, and CON diets. Feeding 30 vs. 15% distillers grains decreased G: F, but including 15% CDG or SDG in SFC-based diets did not affect apparent total tract digestibilities in feedlot steers.