INRA, UR1213 Herbivores, F-63122 Saint-Genès Champanelle, France.
J Anim Sci. 2011 Aug;89(8):2518-28. doi: 10.2527/jas.2010-3140. Epub 2011 Mar 7.
The purposes of this study were 1) to assess the effects of 3 high-concentrate diets on enteric CH(4) production, total tract digestibility, and rumen fermentation of beef cattle, and 2) to evaluate, by life cycle assessment, the potential effects of these feeding systems on the environment. Six bulls (age of 12.4 mo and BW of 417 kg at midexperiment) of the Blond d'Aquitaine breed were assigned to 3 dietary treatments in a replicated 3 × 3 Latin square design. Diets consisted of 1) 49% natural grassland hay, 41% ground corn grain, and 10% soybean meal (hay); 2) 63% corn silage, 21% ground corn grain, and 16% soybean meal (CS); and 3) 70% ground corn grain, 16% soybean meal, and 14% wheat straw (CG). Daily CH(4) emission (g/d), measured using the sulfur hexafluoride tracer technique, was similar for the hay and CS diets and was 56% greater than for the CG diet (P < 0.001). This difference between diets was maintained when CH(4) output was expressed by unit of feed intake (P < 0.001) or digested feed (P < 0.001). Gross energy intake loss as CH(4) averaged 6.9% for the hay and CS diets and 3.2% for the CG diet (P < 0.001). Organic matter intake and GE intake did not differ between diets. Organic matter digestibility was less for the hay diet than for the CS and CG diets (P=0.008). Digestibility of NDF was greatest for the hay diet, intermediate for the CS diet, and least for the CG diet (P=0.02), with ADF digestibility being similar between the hay and CS diets and greater than for the CG diet (P < 0.001). The rumen pH at 5 h postfeeding was less for animals fed the CG diet compared with those fed the other 2 diets (on average, 5.1 vs. 5.9, respectively; P < 0.001). Total CH(4) emission (enteric + manure) was least for the CG diet, whereas N(2)O and CO(2) emissions were greatest for the CG diet. Total greenhouse gas emissions were least for the CG diet when C sequestration by grasslands was not taken into account.
1）评估三种高浓缩饲料对肉牛肠道 CH（4）产生、全肠道消化率和瘤胃发酵的影响，2）通过生命周期评估评估这些饲养系统对环境的潜在影响。在重复的 3x3 拉丁方设计中，将 6 头（试验中期龄为 12.4 个月，体重为 417kg）的 Blonde d'Aquitaine 品种公牛分配到 3 种饮食处理中。饮食由 1）49%天然草原干草、41%地面玉米谷物和 10%大豆粉（干草）；2）63%玉米青贮、21%地面玉米谷物和 16%大豆粉（CS）；和 3）70%地面玉米谷物、16%大豆粉和 14%小麦秸秆（CG）组成。使用六氟化硫示踪技术测量每日 CH（4）排放量（g/d），干草和 CS 饮食的 CH（4）排放量相似，比 CG 饮食高 56%（P < 0.001）。当 CH（4）输出用饲料摄入量（P < 0.001）或消化饲料（P < 0.001）的单位表示时，饮食之间的这种差异仍然存在。干草和 CS 饮食的 CH（4）作为能量摄入损失的平均为 6.9%，CG 饮食为 3.2%（P < 0.001）。有机物质摄入量和 GE 摄入量在饮食之间没有差异。干草饮食的有机物消化率低于 CS 和 CG 饮食（P=0.008）。干草饮食的 NDF 消化率最高，CS 饮食次之，CG 饮食最低（P=0.02），干草和 CS 饮食的 ADF 消化率相似，高于 CG 饮食（P < 0.001）。饲喂 CG 饮食的动物的瘤胃 pH 在饲喂后 5 小时时低于饲喂其他两种饮食的动物（平均分别为 5.1 和 5.9；P < 0.001）。总 CH（4）排放（肠道+粪便）最低的是 CG 饮食，而 CG 饮食的 N（2）O 和 CO（2）排放最高。当不考虑草原的碳封存时，CG 饮食的温室气体总排放量最低。
