Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2010
Publication Date: 7/1/2010
Citation: May, M.L., DeClerck, J.C., Quinn, M.J., DiLorenzo, N., Leibovich, J., Smith, D.R., Hales, K.E., Galyean, M.L. 2010. Corn or sorghum wet distiller's grains with solubles in combination with steam-flaked corn: Feedlot cattle performance, carcass characteristics, and apparent total tract digestibility. Journal of Animal Science. 88:2433-2443. Interpretive Summary: The availablity of ethanol by-products has increased in recent years because of the expansion of the ethanol industry. By-products such as distiller's grains can be efficiently used by ruminants and are a potentially valuable feed resource for finishing beef cattle. However, little research is currently available to understand optimal methods to feed distiller's grains in finishing cattle diets based on steam-flaked corn. Therefore, two studies were conducted to evaluate the value of corn-based and sorghum-based wet distiller's grains with solubles (WDG) on feedlot cattle performance, carcass characteristics, apparent total tract digestion of nutrients, and marker retention time. In Experiment 1, cattle were fed steam flaked corn-based diets consisting of 0, 15, or 30% corn-or sorghum-WDG and 15 or 30% of a 50:50 blend of sorghum and corn WDG. Final body weight and hot carcass weight decreased were noted as level of WDG increased in the diet. Gain efficiency did not differ among the blended, corn-WDG, or control diets containing no WDG. Cattle fed control diets had greater carcass yield grades than those fed diets containing WDG. In Experiment 2, beef steers were fed diets with 0, 15% corn-WDG, or 15%-sorghum WDG. Results suggest that gain efficiency is similar whether including 0 or 15% WDG in the diet. However, when increasing levels (30%) of WDG are included in the diet, gain efficiency is decreased.
Technical Abstract: Two studies were conducted to evaluate corn (CDG) and sorghum (SDG) wet distiller's grains with solubles on feedlot cattle performance, carcass characteristics, apparent total tract digestion of nutrients, and marker retention time. In Experiment 1, 224 steers were used in a randomized complete block design (initial BW 391.1 kg +/- 9.51) and fed steam flaked corn (SFC)-based diets consisting of (DM basis): 0% distillers grains (CON): 15% SDG (SDG-15); 30% SDG (SDG-30); 15% corn (CDG-15); 30% CDG (CDG-30); 15% of a 50:50 blend of SDG and CDG (BDG-15); and 30% of a 50:50 blend of CDG and SDG (BDG-30). Decreased carcass-adjusted final BW and HCW (P < 0.05) were noted as inclusion level of distillers grains increased in the diet. Gain efficiency did not differ among CDG, BDG, and CON treatments, but G:F was numerically less with either level of SDG than for CON, and decreased (P < 0.05) as distiller's grains inclusion level increased from 15 to 30%. Cattle fed CON had greater carcass yield grades than those fed distiller's grains diets (P < 0.05). In Experiment 2, crossbred beef steers (n = 36; initial BW = 567.3 +/- 53.1 kg) were used in a randomized block design and fed SFC-based diets with 0% distiller's grains (CON) and 15% (DM basis) CDG (CDG-15) or SDG (SDG-15). Digestibility and marker retention time were determined with a pulse-dose of Cr2O3. Feeding steers CDG-15 or SDG-15 increased intakes of CP and NDF (P < 0.05), but intakes of DM, OM, ADF, and starch did not differ among treatments (P > 0.07). Neither apparent total tract digestion of DM, OM, CP, NDF, ADF, and starch (P > 0.25) nor marker retention time (P = 0.24) differed among the 3 treatments. Fecal pH averaged over all sampling times was not affected by treatment, nor were average fecal pH values for pre-feeding 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% distiller's grains in the DM, CDG and BDG diets had a similar G:F response to the CON diet, but G:F was less for SDG than for BDG diets. Feeding 30 vs. 15% distiller's grains decreased G:F, but including 15% CDG or SDG in SFC-based diets did not affect apparent total tract digestibility or marker retention time in feedlot steers.