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Energy value of de-oiled modified distillers grains plus solubles in a forage-based diet
An 84-d growing study was conducted utilizing 60 crossbred yearling steers (initial BW = 299 ± 25kg) to determine the energy value of de-oiled modified distillers grains plus solubles (MDGS) using a 2×2+1 factorial arrangement of treatments. Factors were concentration of distillers grains (20 or 40%) and oil content (7.2%, for de-oiled vs. 12.0% for normal). The remainder of the diet was comprised of baled corn residue ground through a 2.54-cm screen. A control diet of 40% dry rolled corn (DRC) was also included. Both de-oiled and normal MDGS were produced at the same plant, and oil was removed by centrifugation of thin stillage. Cattle were fed in an individual Calan gate system once daily with orts collected weekly. There was no MDGS inclusion by fat content interaction between de-oiled and normal MDGS (G:F; P = 0.98). As expected, feeding 40% MDGS resulted in greater ending BW, DMI, ADG, and G:F (P < 0.01) compared to inclusion of 20% MDGS. Steers receiving diets containing de-oiled MDGS had a greater DMI than those fed normal MDGS, 12.7 vs. 11.9 for de-oiled and normal, respectively; (P = 0.05). Ending BW (P = 0.39) were similar for steers fed de-oiled or normal MDGS diets, but steers fed diets containing normal MDGS numerically gained less than those consuming de-oiled MDGS (P = 0.26) diets causing G:F to be unaffected (P = 0.85). Steers consuming the 40% DRC control diet tended to be lighter at the conclusion of the study compared to the those cattle receiving 40% MDGS (P = 0.08). Steers fed 40% DRC had similar DMI compared to steers receiving either 40% de-oiled or normal MDGS (P = 0.28 and P = 0.81 respectively). At 20% inclusion in the diet, steers performed 29.0% less efficiently when compared to the control (P < 0.01) while steers fed 40% MDGS performed 7.9% more efficiently than the control (P < 0.01). The energy value of MDGS relative to corn was calculated to be 124% for these growing calves. The results of this study suggest that removing oil from thin stillage to create MDGS with a fat content of 7.2% vs. 12.0% does not alter cattle performance in forage based diets.
Keywords: corn residue, distillers grains, oil removal