Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada.
J Anim Sci. 2012 Aug;90(8):2802-10. doi: 10.2527/jas.2011-4856. Epub 2012 Jun 4.
Distillers dried grains with solubles (DDGS) are a coproduct of the ethanol industry and are often used as a replacement for grain in livestock production. Feeding corn DDGS to cattle has been linked to increased fecal shedding of Escherichia coli O157:H7, although in Canada, DDGS are often produced from wheat. This study assessed the effects of including 22.5% wheat or corn DDGS (DM basis) into barley-based diets on performance, carcass characteristics, animal health, and fecal E. coli O157:H7 shedding of commercial feedlot cattle. Cattle (n = 6,817) were randomly allocated to 10 pens per treatment group: WDDGS (diets including 22.5% wheat DDGS), CDDGS (diets including 22.5% corn DDGS), or CTRL (barley substituted for DDGS). Freshly voided fecal pats (n = 588) were collected and pooled monthly for fecal pH measurement and screened for naturally occurring E. coli O157:H7 by immunomagnetic separation (IMS) and direct plating (DP). Hide swabs (n = 367) were collected from randomly selected cattle from each pen before slaughter. Pen-floor fecal samples (n = 18) were collected from treatment groups at entry to the feedlot (<14 d on the finishing diet) and after adapting to the finishing diet for ≥ 14 d, inoculated (10(9) cfu of a 5 strain naldixic acid-resistant E. coli O157:H7 mixture), incubated (20°C) and evaluated weekly (IMS and DP) to assess fecal E. coli O157:H7 persistence. The WDDGS group had 3.0% poorer ADG (P = 0.007), 5.3% poorer G:F (P < 0.001), and a decreased proportion of Canada Quality Grade AAA carcasses (P = 0.022) compared with CTRL cattle. The CDDGS group had a similar ADG (P = 0.06), a decreased proportion of Canada Yield Grade (YG) 1 (P < 0.001), and greater proportions of Canada YG 2 (P = 0.003) and YG 3 (P < 0.001) carcasses compared with the CTRL group. There were no differences among groups in any of the animal health parameters assessed. Inclusion of DDGS in cattle finishing diets had no effect on fecal shedding (P = 0.650) or persistence (P = 0.953) of E. coli O157:H7. However, feces from cattle on starter diets <14 d had longer persistence of E. coli O157:H7 (week) than cattle on finishing diets ≥ 14 d (P < 0.003). Inclusion of DDGS in feedlot diets depends on commodity pricing relative to that of barley and for WDDGS must also include the risk of feedlot performance and carcass grading disadvantages. Feeding cattle barley based-diets with 22.5% corn or wheat DDGS did not affect fecal shedding of E. coli O157:H7.
含有可溶物的蒸馏干酒糟（DDGS）是乙醇工业的副产物，通常用作牲畜生产中谷物的替代品。用玉米 DDGS 喂养牛已被证明会增加大肠杆菌 O157:H7 的粪便脱落，但在加拿大，DDGS 通常是由小麦制成的。本研究评估了在以大麦为基础的日粮中添加 22.5%的小麦或玉米 DDGS（DM 基础）对商业肥育牛的生产性能、胴体特性、动物健康和粪便大肠杆菌 O157:H7 脱落的影响。牛（n = 6817）被随机分配到 10 个处理组的每个畜栏：WDDGS（日粮中包括 22.5%的小麦 DDGS）、CDDGS（日粮中包括 22.5%的玉米 DDGS）或 CTRL（用 DDGS 替代大麦）。收集新鲜排出的粪便垫（n = 588），每月一次进行粪便 pH 值测量，并通过免疫磁分离（IMS）和直接平板（DP）筛选天然存在的大肠杆菌 O157:H7。从每个畜栏中随机选择的牛采集皮屑拭子（n = 367）。在肥育牛进入肥育场时（在育肥日粮上 <14 d）和适应育肥日粮至少 14 d 后（接种 5 株耐萘啶酸的大肠杆菌 O157:H7 混合物 10（9）cfu），从处理组收集畜栏地板粪便样本（n = 18）），在 20°C 下孵育并每周评估（IMS 和 DP），以评估粪便大肠杆菌 O157:H7 的持久性。与 CTRL 牛相比，WDDGS 组的 ADG 降低了 3.0%（P = 0.007），G:F 降低了 5.3%（P < 0.001），加拿大质量等级 AAA 胴体的比例降低（P = 0.022）。与 CTRL 组相比，CDDGS 组的 ADG 相似（P = 0.06），加拿大产量等级（YG）1 的比例降低（P < 0.001），加拿大 YG 2（P = 0.003）和 YG 3（P < 0.001）的比例增加。各组之间的任何动物健康参数均无差异。在肥育牛日粮中添加 DDGS 对大肠杆菌 O157:H7 的粪便脱落（P = 0.650）或持久性（P = 0.953）没有影响。然而，在育肥日粮上 <14 d 的牛的粪便中大肠杆菌 O157:H7 的持久性（周）长于在育肥日粮上至少 14 d 的牛（P < 0.003）。在肥育日粮中添加 DDGS 取决于商品价格与大麦的关系，对于 WDDGS，还必须包括肥育性能和胴体分级劣势的风险。用含有 22.5%玉米或小麦 DDGS 的大麦基础日粮喂养牛不会影响大肠杆菌 O157:H7 的粪便脱落。
