214
Impact of feeding distillers grains or isolated components in distillers grains on feedlot performance and carcass traits
The ethanol industry is partially removing corn oil to produce de-oiled distillers with solubles. Additional processing changes (i.e. corn oil, fiber, protein) are underway that will change the nutrient composition and potentially the energy value of distillers grains plus solubles in feedlot diets. An experiment was conducted utilizing 264 crossbred steers (BW= 385 ± 23 kg) in a randomized block design to estimate the energy value of individual components. Diets were formulated to equal the fat, fiber, and protein components of a diet consisting of 40% wet distillers grains plus solubles (WDGS; DM basis). Diets included a corn-based control (CON), WDGS (40% of diet DM) replacing corn, or diets with equal proportions of fiber (FIBER; corn bran and de-oiled germ), protein (PROT; corn gluten meal), or fat (FAT; corn germ) with condensed distillers solubles included at 10% (DM basis). These diets have the same proportions of each component relative to the 40% DGS diet. A 10% condensed distiller solubles (CCDS) diet was also included for comparison of the component diets relative to CON. There were a total of six dietary treatments with five pens/treatment. Dry-matter intake was greatest for FAT and PROT, intermediate for fiber, and least for WDGS, CON, and SOL (P = 0.04). Average daily gain was greatest for WDGS, intermediate for FAT, PROT, and FIBER, and least for SOL and CON (P < 0.01). Feed efficiency was greatest for WDGS, intermediate for CON, SOL, PROT, and FIBER, and least for FAT (P < 0.01). Final carcass adjusted BW and HCW were greatest for WDGS, intermediate for CON, FAT, PROT, and FIBER, and least for SOL (P < 0.01). Fat depth was greatest for DGS, intermediate for PRO, FIBER, and SOL, and least for FAT and CON (P = 0.02). Marbling score and LM area were not different among treatments (P≥ 0.13). Feeding WDGS compared with CON improved feedlot performance and carcass characteristics. It is unclear what component is responsible for improved performance and carcass characteristics when feedlot cattle are fed distillers grains diets compared with a corn-based control diet as no single component fed to steers improved performance as much as WDGS.
Keywords: Components, Distillers grains plus solubles, Feedlot cattle