USDA-ARS-National Laboratory for Agriculture and the Environment, Ames, IA 50011, USA.
J Anim Sci. 2013 Jul;91(7):3231-43. doi: 10.2527/jas.2013-6252.
Two experiments were conducted to determine the DE and ME content of corn distillers dried grains with solubles (corn-DDGS) containing variable ether extract (EE) concentrations and to develop DE and ME prediction equations based on chemical composition. Ether extract content of corn-DDGS ranged from 4.88 to 10.88% (DM basis) among 4 corn-DDGS samples in Exp. 1 and from 8.56 to 13.23% (DM basis) among 11 corn-DDGS samples in Exp. 2. The difference in concentration of total dietary fiber (TDF) and NDF among the 4 corn-DDGS sources was 2.25 and 3.40 percentage units, respectively, in Exp. 1 but was greater among the 11 corn-DDGS sources evaluated in Exp. 2, where they differed by 6.46 and 15.18 percentage units, respectively. The range in CP and ash were from 28.97 to 31.19% and 5.37 to 6.14%, respectively, in Exp. 1 and from 27.69 to 32.93% and 4.32 to 5.31%, respectively, in Exp. 2. Gross energy content among corn-DDGS samples varied from 4,780 to 5,113 kcal/kg DM in Exp. 1 and from 4,897 to 5,167 kcal/kg DM in Exp. 2. In Exp. 1, the range in DE content was from 3,500 to 3,870 kcal/kg DM and ME content varied from 3,266 to 3,696 kcal/kg DM. There were no differences in ME:DE content among the 4 corn-DDGS sources in Exp. 1, but ME:GE content differed (P = 0.04) among sources (66.82 to 74.56%). In Exp. 2, the range in DE content among the 11 corn-DDGS sources was from 3,474 to 3,807 kcal/kg DM and ME content varied from 3,277 to 3,603 kcal/kg DM. However, there were no differences in DE:GE, ME:DE, or ME:GE among sources in Exp. 2. In Exp. 1, no ingredient physical or chemical measurement [bulk density (BD), particle size, GE, CP, starch, TDF, NDF, ADF, hemicellulose, EE, or ash)] was statistically significant at P ≤ 0.15 to predict DE or ME content in corn-DDGS. In Exp. 2, the best fit DE equation was DE (kcal/kg DM) = 1,601 - (54.48 × % TDF) + (0.69 × % GE) + (731.5 × BD) [R(2) = 0.91, SE = 41.25]. The best fit ME equation was ME (kcal/kg DM) = 4,558 + (52.26 × % EE) - (50.08 × % TDF) [R(2) = 0.85, SE = 48.74]. Apparent total tract digestibility of several nutritional components such as ADF, EE, and N were quite variable among corn-DDGS sources in both experiments. These results indicate that although EE may be a good predictor of GE content in corn-DDGS, it is not a primary factor for predicting DE or ME content. Measures of dietary fiber, such as ADF or TDF, are more important than EE in determining the DE or ME content of corn-DDGS for growing pigs.
进行了两项实验，以确定含有不同乙醚提取物（EE）浓度的玉米酒糟干燥物（corn-DDGS）的 DE 和 ME 含量，并基于化学成分开发 DE 和 ME 预测方程。在实验 1 中，4 个 corn-DDGS 样品的 EE 含量范围为 4.88%至 10.88%（DM 基础），在实验 2 中，11 个 corn-DDGS 样品的 EE 含量范围为 8.56%至 13.23%（DM 基础）。在实验 1 中，4 个 corn-DDGS 来源的总膳食纤维（TDF）和 NDF 浓度之间的差异分别为 2.25 和 3.40 个百分点，但在实验 2 中，11 个 corn-DDGS 来源之间的差异更大，分别为 6.46 和 15.18 个百分点。在实验 1 中，CP 和灰分的范围分别为 28.97%至 31.19%和 5.37%至 6.14%，在实验 2 中，CP 和灰分的范围分别为 27.69%至 32.93%和 4.32%至 5.31%。在实验 1 中，corn-DDGS 样品的总能含量范围为 4780 至 5113 千卡/千克 DM，在实验 2 中，总能含量范围为 4897 至 5167 千卡/千克 DM。在实验 1 中，DE 含量范围为 3500 至 3870 千卡/千克 DM，ME 含量范围为 3266 至 3696 千卡/千克 DM。在实验 1 中，4 个 corn-DDGS 来源的 ME:DE 含量没有差异，但 ME:GE 含量存在差异（P = 0.04）（66.82%至 74.56%）。在实验 2 中，11 个 corn-DDGS 来源的 DE 含量范围为 3474 至 3807 千卡/千克 DM，ME 含量范围为 3277 至 3603 千卡/千克 DM。然而，在实验 2 中，来源之间的 DE:GE、ME:DE 和 ME:GE 没有差异。在实验 1 中，没有一种成分的物理或化学测量值[堆密度（BD）、粒径、GE、CP、淀粉、TDF、NDF、ADF、半纤维素、EE 或灰分]在 P ≤ 0.15 时具有统计学意义，无法预测 corn-DDGS 的 DE 或 ME 含量。在实验 2 中，最佳 DE 方程为 DE（千卡/千克 DM）= 1601 -（54.48%×TDF）+（0.69%×GE）+（731.5×BD）[R²= 0.91，SE = 41.25]。最佳 ME 方程为 ME（千卡/千克 DM）= 4558 +（52.26%×EE）-（50.08%×TDF）[R²= 0.85，SE = 48.74]。在这两个实验中，corn-DDGS 来源的几种营养成分的表观全肠道消化率差异很大，如 ADF、EE 和 N。这些结果表明，尽管 EE 可能是 corn-DDGS 中 GE 含量的良好预测指标，但它不是预测 DE 或 ME 含量的主要因素。在确定生长猪 corn-DDGS 的 DE 或 ME 含量时，膳食纤维的测量值（如 ADF 或 TDF）比 EE 更重要。
