Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada, S7N 5A8.
J Dairy Sci. 2012 Feb;95(2):824-41. doi: 10.3168/jds.2011-4718.
A study was conducted to determine the effects of replacing canola meal (CM) as the major protein source with wheat-based dried distillers grains with solubles (W-DDGS) on ruminal fermentation, microbial protein production, omasal nutrient flow and animal performance. Eight lactating dairy cows were fed in a replicated 4 × 4 Latin square design with 28-d periods (20 d of dietary adaptation and 8 d of measurements). Four cows in one Latin square were ruminally cannulated for measurements of ruminal fermentation characteristics and flow of nutrients at the omasal canal. Cows were fed either a standard barley silage-based total mixed ration containing CM as the major protein supplement (0% W-DDGS, control) or diets formulated to contain 10, 15, and 20% W-DDGS (dry matter basis), with W-DDGS replacing primarily CM. Diets were isonitrogenous (18.9% crude protein) and contained 3.0, 3.2, 3.5, and 3.7% ether extract for 0, 10, 15, and 20% W-DDGS, respectively. Diets contained 50% forage and 50% concentrate. Inclusion of W-DDGS linearly increased dry matter intake (29.5, 31.2, 30.2, and 31.9 kg/d for 0, 10, 15, and 20% W-DDGS, respectively). The addition of W-DDGS in place of CM resulted in a 1.2- to 1.8-kg increase in milk yield (42.9, 44.7, 44.1, and 44.5 kg/d for 0, 10, 15, and 20% W-DDGS); however, a quadratic change in feed efficiency (i.e., milk yield/DM intake) occurred as the dietary level of W-DDGS increased. Treatments did not differ for milk fat, protein, and lactose concentrations; however, quadratic changes were observed in milk yields of fat (1.48, 1.56, 1.62, and 1.55 kg/d for 0, 10, 15, and 20% W-DDGS, respectively), protein (1.44, 1.46, 1.49, and 1.42 kg/d) and lactose (1.96, 2.02, 2.09, and 1.93 kg/d). Ruminal fermentation characteristics did not change except that the inclusion of 20% W-DDGS resulted in a decrease and a tendency for a decrease in molar concentrations of isobutyrate and total volatile fatty acids, respectively. Omasal flow of total bacterial nonammonia N (NAN) and bacterial efficiency (g of total bacterial NAN flow/kg of organic matter truly digested in the rumen) were not different among diets; however, feeding W-DDGS resulted in a quadratic increase in nonammonia nonbacterial N flow at the omasal canal (271, 318, 336, and 311 g/d for 0, 10, 15, and 20% W-DDGS, respectively). These data indicate that W-DDGS can substitute for CM as the major protein source in dairy cow diets without negatively affecting ruminal fermentation, microbial protein production, and omasal nutrient flow, and can potentially increase dry matter intake and milk yield.
一项研究旨在确定用基于小麦的干燥酒糟（W-DDGS）替代菜粕（CM）作为主要蛋白质来源对瘤胃发酵、微生物蛋白生产、瘤胃后营养素流量和动物生产性能的影响。8 头泌乳奶牛采用重复 4×4 拉丁方设计进行，为期 28 天（20 天适应饮食，8 天测量）。一个拉丁方中的 4 头奶牛进行瘤胃插管，以测量瘤胃发酵特性和在瘤胃后腔的营养素流量。奶牛分别饲喂标准的大麦青贮基全混合日粮，含有 CM 作为主要蛋白质补充料（0% W-DDGS，对照）或配方日粮，含有 10、15 和 20% W-DDGS（干物质基础），W-DDGS 主要替代 CM。日粮的氮平衡（18.9%粗蛋白）和含有 3.0、3.2、3.5 和 3.7%乙醚提取物，分别为 0、10、15 和 20% W-DDGS。日粮含有 50%粗饲料和 50%精饲料。添加 W-DDGS 线性增加干物质摄入量（29.5、31.2、30.2 和 31.9 kg/d，分别为 0、10、15 和 20% W-DDGS）。用 W-DDGS 替代 CM 可使牛奶产量增加 1.2-1.8 kg（42.9、44.7、44.1 和 44.5 kg/d，分别为 0、10、15 和 20% W-DDGS）；然而，随着日粮 W-DDGS 水平的增加，饲料效率（即牛奶产量/干物质摄入量）呈二次变化。各处理组的牛奶脂肪、蛋白质和乳糖浓度没有差异；然而，在脂肪产量（1.48、1.56、1.62 和 1.55 kg/d，分别为 0、10、15 和 20% W-DDGS）、蛋白质（1.44、1.46、1.49 和 1.42 kg/d）和乳糖（1.96、2.02、2.09 和 1.93 kg/d）方面观察到二次变化。瘤胃发酵特性没有变化，只是添加 20% W-DDGS 导致异丁酸和总挥发性脂肪酸的摩尔浓度分别降低和有降低的趋势。瘤胃后腔的总细菌非氨氮（NAN）和细菌效率（瘤胃中真正消化的有机物质中总细菌 NAN 流量的克数）在日粮之间没有差异；然而，用 W-DDGS 喂养会使瘤胃后腔的非氨非细菌 N 流量呈二次增加（271、318、336 和 311 g/d，分别为 0、10、15 和 20% W-DDGS）。这些数据表明，W-DDGS 可以替代 CM 作为奶牛日粮的主要蛋白质来源，而不会对瘤胃发酵、微生物蛋白生产和瘤胃后营养素流量产生负面影响，并且可以潜在地增加干物质摄入量和牛奶产量。
