The authors would like to thank the staff of the Department of Animal Science&#8217;s Dairy Center for their conscientious care of the experimental cows used to generate data for this study.

参与了代表性的结果中描述的实验动物进行照顾根据宾夕法尼亚州立大学动物护理和使用委员会的指导方针。委员会审议并通过了试验，并在研究进行的所有手续。细节，例如动物和饮食组成信息和实验设计，可在全公布此实验12中找到。 注意:对于设备和进行实验， 参见材料表需要耗材的列表。 1.实验设计<ol><li>获得机构动物护理和使用委员会的批准实验。这是一种非侵入性的过程，不引起疼痛的动物，并归类为USDA C类（ 轻微或瞬间疼痛或痛苦或无疼痛或痛苦 ）。麻醉是没有必要的。 </li><li>选择完整（ 即非空心）牛基于泌乳阶段，年龄，和牛奶产量的实验。不使用空心奶牛瘤胃因为气体通过套管潜在泄漏的同AHCS。设计为缓解这一问题的装置，目前正在测试，但结果并不这里报告。 </li><li>如果交叉设计（即，拉丁方，例如）是利用，使用8至12头奶牛，这取决于治疗次数，在复制的设计为将残余效应均衡。如果，例如，4个处理进行测试，8奶牛将产生一个复制的4×4的设计试验， 等等 。这些类型的实验最小建议持续时间为21至28天，与第一14至21天的适应治疗和7天进行数据收集。 </li><li>如果一个随机区组设计是利用，使用12至15头奶牛每个处理。包括2周协变量周期的数据收集开始之前。这些实验的推荐的持续时间为8至12周时，与第2周贝因克适应治疗。 </li><li>装备各实验动物与ISO 11784或11785兼容的RFID识别标签。 </li></ol>动物2.培训使用AHCS <ol><li>在实验开始前，移动AHCS进入该设施所在的母牛的位置。将单元内的奶牛视力。将本机有至少2天。 </li><li>准备鱼饵饲料的动物一样。不同饲料可以试图吸引牛，虽然（原样重量计）已成功地在实验室中使用的70％磨碎的玉米，27％的干糖浆，和3％的大豆油的混合物。避免可能会堵塞空气过滤器和AHCS的进料输送系统粘和尘土飞扬的饲料。优选的是将进料沉淀。 </li><li>通过将其放置在它们被用于饲料，顶部为了让他们熟悉饵饲料给饲料所有动物的少量（少数）。 </li><li>非常缓慢地移动AHCS到约1.5 M FR嗡的动物。 </li><li>将约1公斤饵料喂成斗让动物香，味饵饲料。渐渐地将水桶朝AHCS单位的料桶，迫使动物伸展和对AHCS料桶达到。 </li><li>转储一些从桶里饵饲料进入AHCS饲槽和缓慢移动AHCS单位对牛。如果在任何时候的训练，牛变成忧虑或恐惧，移动设备远离她，然后再试一次，在另一个时间或日期。 </li><li>在数天的过程中，重复训练直到动物习惯于并且由AHCS单元，（即诱饵饲料）激发。如果动物不能习惯AHCS，替换另一种动物实验开始前和培养遵循上面的程序的新的动物。 </li></ol> 3.校准AHCS的注:CO 2的传感器的浓度范围为0至5％;该范围为CH 4的传感器是0〜2％。检测下限是20 ppm的CH 4和50ppm的CO 2。没有关于甲烷和CO 2的高背景水平的担忧，因为检测限远比在动物设施这些气体的安全高背景水平更大。 <ol><li>为最大的精确度，在每一个气体测量实验结束时执行该校准过程5次在开始时和3次。 </li><li>使用下面的气体（ 见材料表 ）:跨度气体和100％N 2（纯度为99.999％）0.15％CH 4和1％ 的 CO 2（级认证的大师班，精度±2％），零气。 </li><li>填补的样品袋用2L零气体，而另一个袋用2L跨度气体混合物。一定要使用完全瘪袋。填写校准的一天，新的天然气袋。 </li><li> 1年的使用或更少，如果有必要的后更换袋。 </li><li>冒气标准，以其中气体测定实验发生的场所。如果动物与测量发生在一个封闭的工厂（ 即 ，乳品谷仓），在整个校准过程ON打开谷仓的球迷。这是必要的，以减少甲烷浓度在后台空气的效果。 </li><li>打开AHCS开，让校准至少30分钟才温暖。除去从位于前面板内刻度管止挡。确保有处于校准管没有水。除去水，如果需要的话。水会破坏气体浓度传感器。 </li><li>连接N 2袋样品（零气体）校准管。拧下样品袋逆时针1整圈的胶阀允许流动。 </li><li>打开"运行校准"旋钮位于AHCS的仪表控制面板"校准"上。这将开始抽的样品从袋子。一旦流程开始，按按住"校准"按钮约10秒钟，然后松开。 </li><li>等待样品袋放气至约10％其容量的。不要完全清空包包，它可能会损坏传感器。一旦袋约10％的产能，打开"运行校准"按钮返回到"RUN"。 </li><li>关闭样品袋并从刻度管断开。等待2分钟，然后，跨度气体混合物袋连接到刻度管。 </li><li>重复步骤3.7。 </li><li>一旦流程开始后，按住"校准"按钮3秒，然后松开。 </li><li>重复步骤3.10。 </li><li>关闭样品袋并从刻度管断开。更换瓶塞到刻度管。 注:校准完成后，"因子"值将出现在Web页面上的数据卡。的因素变化系数应小于3％，为甲烷和二氧化碳2，R 1％espectively。如果不在该范围内，则重复校准。 </li></ol> 4. CO 2恢复测试<ol><li>在每台气体测量试验前的CO 2回收率试验至少一次（3版本= 1缸CO 2）。在连续应用中，每月进行一次恢复测试。 </li><li>确保CO 2的回收率测试阀关闭（阀是垂直于出口喷嘴）。安装一个新的CO 2缸的发布制度，并打开阀门顺时针，直到紧。 </li><li>能级，零的大规模。将整个释放系统的规模，以确保它是正确的。测试，以确保CO 2的流动:打开开/关阀，并迅速再次关闭它一边听的CO 2离开喷嘴。应当CO 2被流过"whishing"的声音。 </li><li> 二氧化碳钢瓶固定架安装到料桶。从n个流量上，不要让动物们靠近/呼吸进纸器中。人们也不能呼吸放入进纸器。 </li><li>权衡的 CO 2气缸与释放系统。记录这个质量为初始质量。记录在每一个释放 CO 2的开始的当前本地时间。 </li><li>放置的 CO 2气缸和释放系统进入的 CO 2圆筒夹持器（馈送槽）并引导喷嘴进入歧管。不要吸入进纸器中。 </li><li>打开开/关阀，释放的 CO 2，并记录开始释放的时间。后退几英尺远从馈线，并等待3分钟。 3分钟后，关掉释放的开/关阀和记录停止时刻。 </li><li>从送纸器中取出CO 2缸加释放系统。不要拧下释放系统的CO 2缸。握住CO 2缸温水（37〜43℃），浴缸。仅放置在汽缸中的水，而不是整个释放系统。 </li><lI&gt;一旦CO 2筒预热，从水中取出，并用干布，从它擦拭所有的水。称取CO 2缸版本的系统，并记录此作为最终质量。 </li><li>等待至少3分钟的下一版本之前。在3分钟的等待时间，不要让附近单位的任何动物或人。 A 90克Co 2缸可提供约3版本，以便使用多个气瓶，如果有3个以上的版本。当一个液压缸是空的，称量空筒，并继续与一个新的汽缸，如上所述。 </li><li>重复步骤4.3至4.9至少3次，标志着新的开始时间，结束时间，初始质量，以及每个版本的最终质量。 </li><li>最终发布后，至少等待3分钟让动物进入单位之前。完成后，拧下释放系统的CO 2缸。 </li></ol> 5.气体测量注:在气体测量，最近（在一个星期内）AHCS的校准是必需的。见步骤3，AHCS和4， 二氧化碳回收试验标定。确保动物的RFID标签很到位。 <ol><li>上电AHCS和离开30分钟做任何测量前的热身。 </li><li>位置AHCS使气流从谷仓球迷被允许进入料桶。等待2分钟。按FEED交货按钮并保持3秒，提供约50 g饲料的。直观地验证饲料已交付到饲料槽。 </li><li>在牛前辊AHCS。记录在实验笔记本电脑的时间。该装置将读取动物的RFID标签。 </li><li>饲料交付额外的5次超过5分钟的采样周期，间隔他们试图继续保持动物的头，在饲槽。如果额外的饲料是必需的（以保持动物的头进入料桶），记下它的实验笔记本。 </li><li>不E:进料/颗粒通常交付每50秒共6滴（300克/测量事件），得到5分单独测量周期。所述AHCS装有红外传感器来连续地监视动物的相对于进气歧管头​​的距离。这些数据随后被用于确定当动物的头是不是在位置和这些测量数据被丢弃周期。 </li><li>一旦5分钟取样期已过，拉AHCS远离动物和定位装置，使气流从谷仓球迷被允许进入料桶。等待2分钟通过该系统以冲洗空气并收集背景空气组合物的数据。 </li><li>重复步骤5.2至5.5更多的动物。 </li><li>重复取样在24小时的饲养周期的8倍，错开时间超过3天。下面取样时间表已成功地用于:0900，1500，和2100小时（取样天1），0300，1200，和1700小时（取样天2），0000，和0500小时（取样天3）。这种采样时间表将提供8个样品每动物和每个采样周期。采样时间可能因饲养和挤奶时间各不相同。 注意:当气体取样完成时，从该网页中检索发光数据。 </li></ol>

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作者帕特里克·R·齐默尔曼和Scott R.齐默尔曼是C-锁公司共同拥有 （拉皮德城，SD），绿色饲料（AHCS）的制造商说明本条。

所述AHCS系统结合了动态外壳技术中，腔系统，以及用于甲烷和CO 2的质量流量测量示踪技术的元素。在数天的过程中，它收集多个样品从每只动物以限定平均日总气体质量通量。来识别动物和提供诱饵的正确量，RFID读取器被并入AHCS。 RFID标签被读取成动物开始将其头部插入送纸器。一旦动物识别，AHCS确定其是否有资格获得奖励的诱饵在一天中的特定时间（放牧或免费牛舍的应用程序）。每只动物的访问（基于红外传感器确定）的开始和结束时间被自动记录。诱饵递送系统是用来吸引动物AHCS周期性全天。通常，所述诱饵饲料造粒和可以含有草，苜蓿，粒浓缩物，糖蜜，和植物油。虽然动物访问AHCS，风扇拉风了它的头（约26升/分钟的速度），扫发出的CH 4和CO 2到进气歧管。空气流动的速率与一个热膜风速计在空气收集管的中间连续地测量。空气的连续的子样本被提取并传送到次级样品过滤，然后分成两个非分散红外分析仪，一个传感器对CO 2和一个用于CH 4。 AHCS还包括用于空气温度，空气湿度，诱饵降，系统电压，大气压力，丙烷流量，和头部位置的附加传感器。牧草和拖车式版本放牧系统包括一个杯形风速计（当地风速）和风向标（风向）。所有传感器数据被存储在本地的数据记录器和一个计算机，从而使AHCS自动地和独立地发挥作用。传感器数据也存储在内部标准USB（通用串行总线）存储器棒。 AHCS数据通常通过互联网链路传送，每小时一次，在那里它们被永久地记录在外部服务器。与互联网连接，用户可以远程登录到AHCS和控制单元，修改引诱时间表，并查看历史和实时数据，以及审查和监督AHCS功能。 总体而言，在美国宾夕法尼亚州立大学进行的实验表明，AHCS系统提供的甲烷和二氧化碳奶牛装在并列失速谷仓排放可靠的估计。 AHCS超过呼吸室的优点是，动物没有限制，并且是在其天然环境（即，在牧场），或可以自由移动（在自由牛舍）。 AHCS还建立比传统的呼吸室更便宜。此相对低的成本是非常重要的，特别是对CH 4的减轻研究在发展中国家。与SF 6跟踪比较ř方法，AHCS更易于操作，并且不需要复杂且昂贵的分析设备。也许AHCS的最明显的缺点，与商会和SF 6的方法（在放牧或自由牛舍环境中特别是）相比，是动物有主动接近单元，因此气体测量活动都依赖于动物访问。一天之内，这些动物的访问可能会或可能无法代表的CH 4产生的昼夜节律的。因此，在应用中，动物访问AHCS自愿，采样周期应足够长，或重复的足够次数。在宾夕法尼亚州立大学使用的领带摊位申请控制在24小时的饲养周期的数量和气体测量的时间分布，解决了这个问题。嗳气气体的过程中的供给周期（如在上述方案所示）足够采样为representati重要已经估计甲烷产量在牛的瘤胃中。饵饲料的过程中使用AHCS测量供给到动物的量在整体分析（即，必须添加到饲料被动物消耗的总金额），所以每单位进料的发光强度的DMI可以准确要考虑估计。在正常饲养条件下，所述饵料表示的奶牛的总的DMI和其作用，对瘤胃发酵的低于5％和CH 4的产生小。应该注意的是AHCS（和其它类似的系统）不会测量CH 4产生在动物的肠。后肠发酵，但是，有利于仅约3％的总甲烷排放量的在反刍动物7。 根据经验，测量有肠溶瘤胃气体生产中使用AHCS的几个重要组成部分:（1）动物必须习惯于诱饵进料（和AHCS），并具有吨ö喜欢它，以便接近和使用AHCS馈线;（2）动物的头，必须一路插入供给器，以便收集可靠的气体排放数据，（3）的AHCS校准程序，必须严格遵守，（4）具有足够的时间来收集采样个别动物之间的背景的 CH 4和CO 2的数据是重要的，特别是在领带或自由失速谷仓，和（5）是很重要的足够的数据被收集在一个采样周期（覆盖24小时内），以便通过AHCS产生的排数据代表实际的昼夜CH 4或CO 2排放量的动物。 对比测试，AHCS与建立CH 4测量技术支持了上述结论。例如，越来越小母牛的一项研究得出的结论是AHCS是能够从AHCS产生的牲畜和排放估算估算甲烷排放量的可比性由呼吸室 9而得到的值。这些作者指出，部署的AHCS单元和复制​​，必须仔细考虑，以确保足够数量的测量值获得。根据经验，8个采样的事件，交错，在3天时间内以覆盖24小时馈送周期（见协议以上）足以获得气体排放物的准确的测量，并在数据相对低的变异性（即，可接受的精度）。在与哺乳期奶牛的研究中，得出的结论是甲烷排放量由AHCS测量类似于从呼吸室和动物变异性衍生的文献值（11至12％的CV; 0.64〜0.81重复性）也内系列报道的呼吸室10。在最近发表的研究与泌乳牛，AHCS产生了较小的简历比SF 6方法（14.1至22.4％和16.0〜111％的SF 6）13 </SUP&gt;。在宾夕法尼亚州立大学，拥有48泌乳奶牛，在瘤胃甲烷产量抑制了30％（P &lt;0.001），进行了为期12周的实验中，我们得出的结论是AHCS和SF 6方法生产的类似CH 4排放结果:319 481克/每头牛每天（平均374克/ D; SEM = 15.9; CV = 13％）和345 485克/每头牛每天（平均396克/ D; SEM = 29.8; CV = 23 ％）为AHCS 和 SF 6， 分别为14。 总之，准确，但测量甲烷生产在瘤胃中的实用技术是对温室气体减排的努力取得成功至关重要。 AHCS是已被证实可提供肠溶CH 4和CO 2的排放量从肉牛和奶牛的可靠和准确的估算值的自动气体测量系统。

动物产品代表的温室气体（GHG）的全球排放量的显著来源，无论是直接产生甲烷和一氧化二氮（ 例如 ，肠道发酵和粪肥管理）或间接（ 比如 ，从进料，生产活动和转化森林到牧场或农田）。估计全球温室气体排放家畜贡献约7 1〜18％2变化，这取决于所使用的分析和方法的界限。在美国，牲畜为代表的温室气体排放总量的3.1％，2009年3。 肠道CH 4是最大的贡献者来自畜牧业的温室气体排放。因此，动物科学家们发现上缓解技术以减少肠道甲烷生产反刍动物集中他们的研究。在许多情况下，结果是有问题的科学价值，由于实验设计Ø不足R值测量方法1。因此，测量技术的准确度和精密度都严格温室气体减排研究的重要组成部分。大量文献都已经发表了关于这个话题在近几年4-7。有几种方法建立用于测量肠溶CH 4产生于反刍动物，包括呼吸室（高度准确的，但具有有限的适用性），示踪气体（六氟化硫; SF 6），和头腔室。虽然呼吸室被认为是"金标准"，用于测量瘤胃气体排放，其主要缺点是，动物的审判的数量通常是由于在某一特定研究机构提供商会在有限数量的限制。用于测量肠溶CH 4产生最实际和广泛使用的技术是对SF 6示踪气体的方法，最近，一个自动头室系统（AHCS，绿色饲料）将c一个监视器甲烷和CO 2的质量通量从8反刍动物的呼吸和嗳气气。无论是SF 6技术和AHCS使排放量要在自由放牧条件下或在自由和领带摊位谷仓大量动物的分析。的SF 6技术利用SF 6作为示踪气体，它是连续地从在呼出气体的样品的动物，收集的瘤胃插入渗透管，气体的分析适用于SF 6释放:CH 4比。 AHCS]是也基于使用示踪气体（丙烷）的自动化，头部室型系统。与呼吸腔室的方法，其中动物异常馈送和行为的条件下密闭，并通过SF 6示踪方法，该方法需要特殊的分析能力和设备（气体收集和 SF 6分析）以及大量的动物处理相比，AHCS是非-intrusive并且不太昂贵的掌握和操作。 AHCS的主要缺点包括不具代表性的采样（在应用，如放牧系统，其中，动物必须自愿访问单元），并使用诱饵饲料，这可能的气体测量期间表示多达动物的干物质摄取量的5％事件。最近的对比实验得出的结论是AHCS产生的排放率与那些使用呼吸室或SF 6技术9,10估计。 单机AHCS系统是围绕一个强大的自动进给器是易于运输通过手工或可被安装到装备有太阳能电池板（或其他电源），用于自主现场操作和长途旅行的拖车构成。该系统包括一个动物射频识别系统（RFID），一个诱饵系统，空气处理和测量系统，气体示踪系统，电子设备和通信系统，以及一个数据处理系统（&lt;STRONG&gt;图1）。更多细节可以在原专利文献11中找到。 下面介绍的例子AHCS操作协议是奶牛装在一个领带牛舍。该过程也适用于其他类型的容纳在类似设施牛（非哺乳期奶牛，小母牛，或肉牛）的。该实验的目的是证明AHCS的原理和操作为甲烷和二氧化碳从反刍动物排放的测量。

<table><tbody><tr><td>AHCS</td><td>1</td><td>C-Lock, Inc.</td><td></td></tr><tr><td>Zero, 100 N&lt;sub&gt;2&lt;/sub&gt;</td><td>1</td><td>Air Liquide</td><td>4 m&lt;sup&gt;3&lt;/sup&gt; sized tanks filled with&amp;nbsp; 13,790 kPa</td></tr><tr><td>Span, 0.15% CH&lt;sub&gt;4 &lt;/sub&gt;and 1% CO&lt;sub&gt;2&lt;/sub&gt;</td><td>1</td><td>Air Liquide</td><td>4 m&lt;sup&gt;3&lt;/sup&gt; sized tanks filled with 13,790 kPa</td></tr><tr><td>Gas sampling bag</td><td>2</td><td>SKC, Inc.</td><td>FlexFoil&amp;reg; PLUS Breath-gas analysis bags</td></tr><tr><td>Gas regulator</td><td>2</td><td>Scott Gasses</td><td></td></tr><tr><td>CO&lt;sub&gt;2&lt;/sub&gt; cylinder</td><td>6</td><td>JT</td><td>90 g CO&lt;sub&gt;2&lt;/sub&gt; tanks</td></tr><tr><td>Mass scale</td><td>1</td><td>A&amp;amp;D EJ6100</td><td>&gt;4 kg, with 0.1 g resolution</td></tr><tr><td>Propane cylinder 485 ml</td><td>1</td><td>Coleman</td><td></td></tr><tr><td>ISO 11784/11785 button ear tag</td><td>40</td><td>Allflex USA</td><td>One tag per animal</td></tr><tr><td>Alleyway (for free-stalls, tie-stalls)</td><td>2</td><td>Behlen Country</td><td>One alleyway per unit</td></tr><tr><td>30 m AC extension cord</td><td>1</td><td>HDX</td><td></td></tr><tr><td>A container with warm water (37-43 &amp;deg;C)</td><td>1</td><td>N/A</td><td></td></tr><tr><td>Stopwatch (sec)</td><td>1</td><td>N/A</td><td></td></tr></tbody></table>

the use of an automated system (greenfeed) to monitor enteric methane and carbon dioxide emissions from ruminant animals

反刍动物（驯养的或野生）发射甲烷 （CH 4）通过肠道发酵在他们的消化道和从储存期间粪肥的分解。这些过程的温室气体（GHG）从动物生产系统排放的主要来源。用于测量肠溶CH 4技术从直接测量不同（呼吸腔室，这是高度精确的，但具有有限的适用性）各种间接方法（监听器，激光技术，这是实际的，但具有可变的准确度）。六氟化硫（SF 6）示踪气体方法是常用的动物科学家，最近来衡量肠道甲烷生产，应用的自动头腔系统（AHCS）（绿色饲料，C-锁公司，拉皮德城的， SD），这是该实验的焦点，一直在增长。 AHCS是一个自动化的系统来监控甲烷和二氧化碳（CO 2）从质量通量呼吸反刍动物。在一个典型的AHCS操作，小批量下料的饲料被分配到各个动物每天吸引他们到AHCS多次。当动物访问AHCS，风扇系统能让空气经过动物的枪口入进气歧管，并通过空气收集管，其中连续气流速率进行测量。空气的子样本被泵出管的成非色散红外线传感器的 CH 4和CO 2浓度的连续测量。 AHCS对呼吸室或SF 6场的比较表明，AHCS产生重复和精确的CH 4排放的结果，前提是动物参观AHCS都足以使排放量估计有代表性瘤胃产气的昼夜节律。在这里，我们演示了如何使用AHCS的从给予控制饮食或补充工业级腰果饮食奶牛4通量测量二氧化碳和甲烷外壳液体。

<img alt="图1" src="/files/ftp_upload/52904/52904fig1.jpg" /> 图1:自动头部室系统（AHCS，绿色饲料）的用于测量CH 4产生在反刍动物的组件。 甲烷产生在瘤胃是衬底依赖性微生物过程7。生产中的CH 4和CO 2的增加后的动物饲喂，降低其后。 图2显示从奶牛自由进食（由AN赫里斯托夫，宾夕法尼亚州立大学未公布的数据）增加的CH 4产生在约0600 小时 。 <img alt="图2" src="/files/ftp_upload/52904/52904fig2.jpg" /> 图2:日CH从测量喂一次每日奶牛4排放量使用AHCS（误差棒代表SE;数据来源AN赫里斯托夫，笔nsylvania州立大学）。 在此图中的误差线代表过程的取样事件（包括多个嗳气循环）变异的CH 4排放 。显而易见的是，在一些情况下（大约0400和0900小时），变异性是由于改变呼出的气体CH 4的浓度大。它同样清楚的是甲烷排放量喂食后增加（这是周围0600小时在这个例子中）。每日平均CH 4排放 （ 即 ，平均13个测量事件）的这头牛是727±22.9克/天，或26克/公斤时，每千克日粮干物质采食量（DMI）的表达。 为了证明CH的范围从一组使用AHCS测量泌乳奶牛4排放量，我们包括在宾夕法尼亚州立大学最近进行的一项交叉设计试验，采用工业级腰果壳液为CH 4数据<html>缓解剂（ 表1）。审讯是在8头泌乳荷斯坦奶牛每21天2实验阶段。在每个周期的最后一周收集甲烷的数据。甲烷排放数据不是从一头牛收集在第1期和那头牛数据也没有时间用实验2的细节可以在布兰科等人 12发现。在这项研究中的平均CO 2的排放量为每天超过18,000个克/牛，或634克/千克的DMI。平均CH 4的排放为这组母牛为五百二十三克/天或20克/公斤的DMI，这是类似的平均甲烷排放报告了超过370处理装置（19.1±0.43克/公斤的DMI）7的数据集。在研究表 1中所示，与对照组相比，工业级腰果壳油倾向于由约5％（P = 0.08）12，以减少甲烷产量的奶牛瘤胃。 e_content"&gt; <img alt="表1" src="/files/ftp_upload/52904/52904table1.jpg" />

Watch this Scientific Journal Video about The Use of an Automated System GreenFeed to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals at JoVE.com

The Use of an Automated System GreenFeed to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals

Accuracy and precision of the techniques used to measure methane emissions from ruminant animals are critically important for the success of greenhouse gas mitigation efforts. This manuscript describes the principles and operation of an automated system to monitor methane and carbon dioxide mass fluxes from the breath of ruminant animals.

自动系统（绿色饲料）的用于监视肠道的甲烷和二氧化碳从反刍动物排放

Ruminant animals (domesticated or wild) emit methane (CH4) through enteric fermentation in their digestive tract and from decomposition of manure during ...

the-use-an-automated-system-greenfeed-to-monitor-enteric-methane

Nanyang Technological University

Research

JoVE Journal

Environment

The Use of an Automated System (GreenFeed) to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals

21.7K 次观看.  Pennsylvania State University. Accuracy and precision of the techniques used to measure methane emissions from ruminant animals are critically important for the success of greenhouse gas mitigation efforts. This manuscript describes the principles and operation of an automated system to monitor methane and carbon dioxide mass fluxes from the breath of ruminant animals.

视频: The Use of an Automated System GreenFeed to Monitor Enteric Methane and Carbon Dioxide Emissions from Ruminant Animals

Measurement of Greenhouse Gas Flux from Agricultural Soils Using Static Chambers

Measurement of greenhouse gas (GHG) fluxes between the soil and the atmosphere, in both managed and unmanaged ecosystems, is critical to understanding the biogeochemical drivers of climate change and to the development and evaluation of GHG mitigation strategies based on modulation of landscape management practices. The static chamber-based method described here is based on trapping gases emitted from the soil surface within a chamber and collecting samples from the chamber headspace at regular intervals for analysis by gas chromatography. Change in gas concentration over time is used to calculate flux. This method can be utilized to measure landscape-based flux of carbon dioxide, nitrous oxide, and methane, and to estimate differences between treatments or explore system dynamics over seasons or years. Infrastructure requirements are modest, but a comprehensive experimental design is essential. This method is easily deployed in the field, conforms to established guidelines, and produces data suitable to large-scale GHG emissions studies.

This article showcases the static chamber-based method for measurement of greenhouse gas flux from soil systems. With relatively modest infrastructure investments, measurements may be obtained from multiple treatments/locations and over timeframes ranging from hours to years.

从农业土壤使用静态钱伯斯温室气体流量测量

Measurement of greenhouse gas (GHG) fluxes between the soil and the atmosphere, in both managed and unmanaged ecosystems, is critical to understanding the ...

科研

环境科学

Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA libraries are needed for optimal results from next-generation sequencing. Environmental samples such as water may have low quality and quantities of DNA as well as contaminants that co-precipitate with DNA. The mechanical and enzymatic processes involved in extraction and library preparation may further damage the DNA. Gel size selection enables purification and recovery of DNA fragments of a defined size for sequencing applications. Nevertheless, this task is one of the most time-consuming steps in the DNA library preparation workflow. The protocol described here enables complete automation of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments. 
In this study, we describe a high-throughput approach to prepare high quality DNA libraries from freshwater samples that can be applied also to other environmental samples. We used an indirect approach to concentrate bacterial cells from environmental freshwater samples; DNA was extracted using a commercially available DNA extraction kit, and DNA libraries were prepared using a commercial transposon-based protocol. DNA fragments of 500 to 800 bp were gel size selected using Ranger Technology, an automated electrophoresis workstation. Sequencing of the size-selected DNA libraries demonstrated significant improvements to read length and quality of the sequencing reads.

This manuscript describes an automated gel size selection approach for purifying DNA fragments for next-generation sequencing. The Ranger Technology provides complete automation of the entire process of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments allowing for high-throughput and high quality next-generation sequencing libraries.

自动凝胶尺寸选择，以提高下一代测序文库的质量，从环境水样准备

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA ...

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given.

Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

The European Commission has developed a Real-Driving Emissions (RDE) test procedure to verify pollutant emissions during real-world vehicle operation using the Portable Emissions Measurement Systems (PEMS). This paper presents the experimental procedures required by the newly-adopted RDE test.

便携式排放测量系统（PEMS）在欧洲的真实驾驶排放（RDE）规例的执行情况

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. ...

Continuously-stirred Anaerobic Digester to Convert Organic Wastes into Biogas: System Setup and Basic Operation

Anaerobic digestion (AD) is a bioprocess that is commonly used to convert complex organic wastes into a useful biogas with methane as the energy carrier 1-3. Increasingly, AD is being used in industrial, agricultural, and municipal waste(water) treatment applications 4,5. The use of AD technology allows plant operators to reduce waste disposal costs and offset energy utility expenses. In addition to treating organic wastes, energy crops are being converted into the energy carrier methane 6,7. As the application of AD technology broadens for the treatment of new substrates and co-substrate mixtures 8, so does the demand for a reliable testing methodology at the pilot- and laboratory-scale.
Anaerobic digestion systems have a variety of configurations, including the continuously stirred tank reactor (CSTR), plug flow (PF), and anaerobic sequencing batch reactor (ASBR) configurations 9. The CSTR is frequently used in research due to its simplicity in design and operation, but also for its advantages in experimentation. Compared to other configurations, the CSTR provides greater uniformity of system parameters, such as temperature, mixing, chemical concentration, and substrate concentration. Ultimately, when designing a full-scale reactor, the optimum reactor configuration will depend on the character of a given substrate among many other nontechnical considerations. However, all configurations share fundamental design features and operating parameters that render the CSTR appropriate for most preliminary assessments. If researchers and engineers use an influent stream with relatively high concentrations of solids, then lab-scale bioreactor configurations cannot be fed continuously due to plugging problems of lab-scale pumps with solids or settling of solids in tubing. For that scenario with continuous mixing requirements, lab-scale bioreactors are fed periodically and we refer to such configurations as continuously stirred anaerobic digesters (CSADs).
This article presents a general methodology for constructing, inoculating, operating, and monitoring a CSAD system for the purpose of testing the suitability of a given organic substrate for long-term anaerobic digestion. The construction section of this article will cover building the lab-scale reactor system. The inoculation section will explain how to create an anaerobic environment suitable for seeding with an active methanogenic inoculum. The operating section will cover operation, maintenance, and troubleshooting. The monitoring section will introduce testing protocols using standard analyses. The use of these measures is necessary for reliable experimental assessments of substrate suitability for AD. This protocol should provide greater protection against a common mistake made in AD studies, which is to conclude that reactor failure was caused by the substrate in use, when really it was improper user operation 10.

Laboratory-scale anaerobic digesters allow scientists to research new ways of optimizing existing applications of anaerobic biotechnology and to evaluate the methane producing potential of various organic wastes. This article introduces a generalized model for the construction, inoculation, operation, and monitoring of a laboratory-scale continuously stirred anaerobic digester.

连续搅拌厌氧消化有机废物转化为沼气系统的安装和基本操作

Anaerobic digestion (AD) is a bioprocess that is commonly used to convert complex organic wastes into a useful biogas with methane as the energy carrier ...

生物工程

Assessment of Methane and Nitrous Oxide Fluxes from Paddy Field by Means of Static Closed Chambers Maintaining Plants Within Headspace

This protocol describes the measurement of greenhouse gas (GHG) emissions from paddy soils using the static closed chamber technique. This method is based on the diffusion theory. A known volume of air overlaying a defined soil area is enclosed within a parallelepiped cover (named &#34;chamber&#34;), for a defined period of time. During this enclosure period, gases (methane (CH4) and nitrous oxide (N2O)) move from soil pore air near their microbial source (i.e., methanogens, nitrifiers, denitrifiers) to the chamber headspace, following a natural concentration gradient. Fluxes are then estimated from chamber headspace concentration variations sampled at regular intervals throughout the enclosure and then analyzed with gas chromatography. Among the techniques available for GHG measurement, the static closed chamber method is suitable for plot experiments, as it does not require large homogenously treated soil areas. Furthermore, it is manageable with limited resources and can identify relationships among ecosystem properties, processes, and fluxes, especially when combined with GHG driving force measurements. Nevertheless, with respect to the micrometeorological method, it causes a minimal but still unavoidable soil disturbance, and allows a minor temporal resolution. Several phases are key to the method implementation: i) chamber design and deployment, ii) sample handling and analyses, and iii) flux estimation. Technique implementation success in paddy fields demands adjustments for field flooding during much of the cropping cycle, and for rice plant maintenance within the chamber headspace during measurements. Therefore, the additional elements to be considered with respect to the usual application of non-flooded agricultural soils consist of devices for: i) avoiding any unintended water disturbance that could overestimate fluxes, and ii) including rice plants within the chamber headspace to fully consider gases emitted through aerenchyma transportation.

The overall goal of this protocol is to measure greenhouse gas emissions from paddy fields using the static closed chamber technique. The measurement system needs specific adjustments due to the presence of both a permanent water layer in the field and of the plants within the chamber headspace.

用静止封闭室维持顶空装置对稻田甲烷和一氧化二氮通量的评价

This protocol describes the measurement of greenhouse gas (GHG) emissions from paddy soils using the static closed chamber technique. This method is based ...

Lab-Scale Model to Evaluate Odor and Gas Concentrations Emitted by Deep Bedded Pack Manure

A lab-scaled simulated bedded pack model was developed to study air quality and nutrient composition of deep-bedded packs used in cattle mono-slope facilities. This protocol has been used to effectively evaluate many different bedding materials, environmental variables (temperature, humidity), and potential mitigation treatments that can improve air quality in commercial deep-bedded mono-slope facilities. The model is dynamic and allows researchers to easily collect many chemical and physical measurements from the bedded pack. Weekly measurements, collected over the course of six to seven weeks, allows sufficient time to see changes in air quality measurements over time as the bedded pack matures. The data collected from the simulated bedded packs is within the range of concentrations previously measured in commercial deep-bedded mono-slope facilities. Past studies have demonstrated that 8 - 10 experimental units per treatment are sufficient to detect statistical differences among the simulated bedded packs. The bedded packs are easy to maintain, requiring less than 10 minutes of labor per bedded packs per week to add urine, feces, and bedding. Sample collection using the gas sampling system requires 20 - 30 minutes per bedded pack, depending on the measurements that are being collected. The use of lab-scaled bedded packs allows the researcher to control variables such as temperature, humidity, and bedding source that are difficult or impossible to control in a research or commercial facility. While not a perfect simulation of &#34;real-world&#34; conditions, the simulated bedded packs serve as a good model for researchers to use to examine treatment differences among bedded packs. Several lab-scale studies can be conducted to eliminate possible treatments before trying them in a research or commercial-sized facility.

A protocol has been developed to measure gases, odors, and nutrient composition in lab-scaled bedded manure packs, which can be used to study ways to improve air quality in commercial cattle facilities using deep-bedded manure packs.

用实验室尺度模型评价深层包粪排放的恶臭和气体浓度

A lab-scaled simulated bedded pack model was developed to study air quality and nutrient composition of deep-bedded packs used in cattle mono-slope ...

Design and Use of a Full Flow Sampling System (FFS) for the Quantification of Methane Emissions

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas industry faces continued scrutiny for methane emissions from across the supply chain, due to methane&#39;s relatively high global warming potential (25-84x that of carbon dioxide, according to the Energy Information Administration). Currently, a variety of techniques of varied uncertainties exists to measure or estimate methane emissions from components or facilities. Currently, only one commercial system is available for quantification of component level emissions and recent reports have highlighted its weaknesses.
In order to improve accuracy and increase measurement flexibility, we have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases based on transportation emissions measurement principles. The FFS is a modular system that consists of an explosive-proof blower(s), mass airflow sensor(s) (MAF), thermocouple, sample probe, constant volume sampling pump, laser based greenhouse gas sensor, data acquisition device, and analysis software. Dependent upon the blower and hose configuration employed, the current FFS is able to achieve a flow rate ranging from 40 to 1,500 standard cubic feet per minute (SCFM). Utilization of laser-based sensors mitigates interference from higher hydrocarbons (C2+). Co-measurement of water vapor allows for humidity correction. The system is portable, with multiple configurations for a variety of applications ranging from being carried by a person to being mounted in a hand drawn cart, on-road vehicle bed, or from the bed of utility terrain vehicles (UTVs). The FFS is able to quantify methane emission rates with a relative uncertainty of &#177; 4.4%. The FFS has proven, real world operation for the quantification of methane emissions occurring in conventional and remote facilities.

Design and Use of a Full Flow Sampling System FFS for the Quantification of Methane Emissions

We have designed, developed, and implemented a novel full flow sampling system (FFS) for quantification of methane emissions and greenhouse gases from across the natural gas supply chain.

设计和全流采样系统（FFS）的使用甲烷排放的量化

The use of natural gas continues to grow with increased discovery and production of unconventional shale resources. At the same time, the natural gas ...

工程学

用于从猪废沼气中获取生物甲烷的微藻培养

Biogas Purification through the use of a Microalgae-Bacterial System in Semi-Industrial High Rate Algal Ponds

In recent years, a number of technologies have emerged to purify biogas into biomethane. This purification entails a reduction in the concentration of polluting gases such as carbon dioxide and hydrogen sulfide to increase the content of methane. In this study, we used a microalgal cultivation technology to treat and purify biogas produced from organic waste from the swine industry to obtain ready-to-use biomethane. For cultivation and purification, two 22.2 m3 open-pond photobioreactors coupled with an absorption-desorption column system were set up in San Juan de los Lagos, Mexico. Several recirculation liquid/biogas ratios (L/G) were tested to obtain the highest removal efficiencies; other parameters, such as pH, dissolved oxygen (DO), temperature, and biomass growth, were measured. The most efficient L/Gs were 1.6 and 2.5, resulting in a treated biogas effluent with a composition of 6.8%vol and 6.6%vol in CO2, respectively, and removal efficiencies for H2S up to 98.9%, as well as maintaining O2 contamination values of less than 2%vol. We found that pH greatly determines CO2 removal, more so than L/G, during cultivation because of its participation in the photosynthetic process of microalgae and its ability to vary pH when solubilized due to its acidic nature. DO, and temperature oscillated as expected from the light-dark natural cycles of photosynthesis and the time of day, respectively. Biomass growth varied with CO2 and nutrient feeding as well as reactor harvesting; however, the trend remained primed for growth.

作者聚焦:扩展微藻生物技术以提高生物甲烷产量 

Air pollution impacts the quality of life of all organisms. Here, we describe the use of microalgae biotechnology for the treatment of biogas (simultaneous removal of carbon dioxide and hydrogen sulfide) and the production of biomethane through semi-industrial open high-rate algal ponds and subsequent analysis of treatment efficiency, pH, dissolved oxygen, and microalgae growth.

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化

In recent years, a number of technologies have emerged to purify biogas into biomethane. This purification entails a reduction in the concentration of ...

自动系统（绿色饲料）的用于监视肠道的甲烷和二氧化碳从反刍动物排放

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从农业土壤使用静态钱伯斯温室气体流量测量

自动凝胶尺寸选择，以提高下一代测序文库的质量，从环境水样准备

便携式排放测量系统（PEMS）在欧洲的真实驾驶排放（RDE）规例的执行情况

连续搅拌厌氧消化有机废物转化为沼气系统的安装和基本操作

用静止封闭室维持顶空装置对稻田甲烷和一氧化二氮通量的评价

用实验室尺度模型评价深层包粪排放的恶臭和气体浓度

设计和全流采样系统（FFS）的使用甲烷排放的量化

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化

在半工业化高速率藻类池塘中使用微藻细菌系统进行沼气净化