Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, T1J 4B1, Canada.
J Anim Sci. 2011 Aug;89(8):2491-501. doi: 10.2527/jas.2010-3418. Epub 2011 Mar 31.
The objective of this study was to evaluate the effects of substituting wheat dried distillers grains with solubles (DDGS) for barley grain and barley silage on intake, digestibility, and ruminal fermentation in feedlot beef cattle. Eight ruminally cannulated Angus heifers (initial BW 455 ± 10.8 kg) were assigned to a replicated 4 × 4 Latin square design with 4 treatments: control, low (25%), medium (30%), and high (35%) wheat DDGS (DM basis). The diets consisted of barley silage, barley concentrate, and wheat DDGS in ratios of 15:85:0 (CON), 10:65:25 (25DDGS), 5:65:30 (30DDGS), and 0:65:35 (35DDGS; DM basis), respectively. The diets were formulated such that wheat DDGS was substituted for both barley grain and barley silage to evaluate whether wheat DDGS can be fed as a source of both energy (grain) and fiber in feedlot finishing diets. Intakes (kg/d) of DM and OM were not different, whereas those of CP, NDF, ADF, and ether extract (EE) were greater (P < 0.01) and intake of starch was less (P < 0.01) for the 25DDGS compared with the CON diet. The digestibilities of CP, NDF, ADF, and EE in the total digestive tract were greater (P < 0.05) for 25DDGS vs. CON. Ruminal pH and total VFA concentrations were not different (P > 0.15) between 25DDGS and CON diets. Replacing barley silage with increasing amounts of wheat DDGS (i.e., from 25DDGS to 35DDGS) linearly reduced (P < 0.05) intakes of DM and other nutrients without altering (P=0.40) CP intake. In contrast, digestibilities of DM and other nutrients in the total digestive tract linearly increased (P < 0.05) with increasing wheat DDGS except for that of EE. Additionally, with increasing amounts of wheat DDGS, mean ruminal pH tended (P=0.10) to linearly decrease, and ruminal pH status decreased with longer (P=0.04) duration of pH <5.5 and <5.2, and greater (P=0.01) curve area under pH <5.8 and <5.5 without altering (P > 0.19) ruminal VFA and NH(3)-N concentrations. Results indicated that wheat DDGS can be effectively used to replace both barley grain and silage at a moderate amount to meet energy and fiber requirements of finishing cattle. However, when silage content of the diet is low (<10%), wheat DDGS is not an effective fiber source, so replacing forage fiber with wheat DDGS in finishing diets decreases overall ruminal pH status even though the rapidly fermentable starch content of the diet is considerably reduced.
本研究旨在评估用小麦干酒糟及其可溶物（DDGS）替代大麦谷物和大麦青贮饲料对育肥牛采食量、消化率和瘤胃发酵的影响。8 头瘤胃内置有套管的安格斯小母牛（初始 BW 455±10.8kg）被分配到一个重复 4×4 拉丁方设计中，有 4 个处理：对照组、低（25%）、中（30%）和高（35%）小麦 DDGS（DM 基础）。日粮由大麦青贮、大麦浓缩物和小麦 DDGS 组成，比例分别为 15:85:0（CON）、10:65:25（25DDGS）、5:65:30（30DDGS）和 0:65:35（35DDGS；DM 基础）。日粮的设计是用小麦 DDGS 替代大麦谷物和大麦青贮，以评估小麦 DDGS 是否可以作为育肥日粮中能量（谷物）和纤维的来源。DM 和 OM 的采食量（kg/d）没有差异，而 CP、NDF、ADF 和乙醚提取物（EE）的采食量更高（P<0.01），淀粉的采食量更低（P<0.01）25DDGS 组与 CON 组相比。25DDGS 组的 CP、NDF、ADF 和 EE 在整个消化道的消化率更高（P<0.05）。25DDGS 和 CON 日粮之间的瘤胃 pH 和总 VFA 浓度没有差异（P>0.15）。随着小麦 DDGS 用量的增加（即从 25DDGS 到 35DDGS），替代大麦青贮饲料线性降低了 DM 和其他营养素的采食量（P<0.05），而 CP 的采食量没有改变（P=0.40）。相反，DM 和其他营养素在整个消化道的消化率随着小麦 DDGS 用量的增加而线性增加（P<0.05），除 EE 外。此外，随着小麦 DDGS 用量的增加，平均瘤胃 pH 值呈线性下降趋势（P=0.10），随着 pH 值<5.5 和<5.2 的时间延长（P=0.04）和 pH 值<5.8 和<5.5 的曲线下面积增加（P=0.01），而瘤胃 VFA 和 NH3-N 浓度没有改变（P>0.19）。结果表明，小麦 DDGS 可以有效地替代大麦谷物和青贮饲料的中等用量，以满足育肥牛的能量和纤维需求。然而，当日粮中青贮饲料含量较低（<10%）时，小麦 DDGS 不是一种有效的纤维来源，因此用小麦 DDGS 替代育肥日粮中的饲草纤维会降低整体瘤胃 pH 值，尽管日粮中快速发酵淀粉的含量显著降低。
