Two experiments were conducted to determine the potential for the essential oil blend Agolin Ruminant L (Agolin) to reduce enteric methane (CH4) emissions from beef cattle when delivered via the drinking water. Experiment 1 evaluated aqueous solutions of Agolin (50 mg/L) and a non-protein nitrogen and mineral solution (uPRO ORANGE [uPRO]; 1.7 mL/L) individually and in combination, where Agolin was added to concentrated uPRO at 3, 4.5, 6% Agolin (w/w) prior to dilution with water at 1.7 mL/L, for a total of five treatments. These were incubated for 48 h with a medium-quality Rhodes grass (Chloris gayana) hay substrate, with gas production, CH4 concentration in gas, and digestibility measured in vitro. In Exp. 2, Droughtmaster steers (n = 24) were fed a basal diet of Rhodes grass hay and were allocated to one of three water treatments (n = 8/treatment) supplemented with either uPRO (2.27 mL uPRO/L water), or one of two inclusion rates of Agolin in combination with uPRO (2.27 mL uPRO and 6 µL Agolin/L water or 2.27 mL uPRO and 24 µL Agolin/L water) with enteric CH4 emissions, feed and water intake, and live weight gain (LWG) measured over 56 d. In Exp. 1, the inclusion of Agolin in uPRO at 6% w/w resulted in a reduction in CH4 production (15.8%; P = 0.003) and the proportion of CH4 in the gas produced (24.5%; P < 0.001). In Exp. 2, steers consuming the lower quantity of Agolin via drinking water had a 16.4% (P = 0.0027) reduction in CH4 production over the experiment, declining from 140 g/d during week 1 to 117 g/d in week 8. This inclusion rate of Agolin in the drinking water also resulted in a 25 g (17.6%) CH4/d decrease in emissions by steers compared to control steers (P = 0.0205). However, no significant differences in CH4 yield (g CH4/kg dry matter intake), or CH4 intensity (g CH4/kg LWG) by steers was observed between treatments. These results demonstrate that Agolin reduces CH4 emissions when mixed in aqueous solution under in vitro and in vivo conditions, providing a potential method to reduce enteric CH4 emissions from cattle in extensive production systems.

中文翻译：

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精油混合物 Agolin Ruminant L 包含在牛的饮用水中时，可减少体外和体内甲烷的产生


进行了两项实验，以确定精油混合物 Agolin Ruminant L （Agolin） 在通过饮用水输送时减少肉牛肠道甲烷 （CH4） 排放的潜力。实验 1 单独和组合评估了 Agolin （50 mg/L） 和非蛋白氮和矿物溶液 （uPRO ORANGE [uPRO];1.7 mL/L） 的水溶液，其中将 Agolin 添加到 3、4.5、6% Agolin （w/w） 的浓缩 uPRO 中，然后用 1.7 mL/L 的水稀释，总共进行了 5 次处理。将它们与中等质量的罗德草 （Chloris gayana） 干草基质一起孵育 48 小时，产生气体，气体中的 CH4 浓度，并在体外测量消化率。在实验 2 中，Droughtmaster 公牛 （n = 24） 饲喂罗得岛草干草基础饲料，并分配到三种水处理之一（n = 8/处理），补充 uPRO（2.27 mL uPRO/L 水），或两种 Agolin 与 uPRO 组合的添加率之一（2.27 mL uPRO 和 6 μL Agolin/L 水或 2.27 mL uPRO 和 24 μL Agolin/L 水）与肠道 CH4 排放， 在 56 天内测量的采食量和水摄入量以及活重增加 （LWG）。在实验 1 中，将 Agolin 以 6% w/w 的浓度加入 uPRO 导致 CH4 产量减少（15.8%;P = 0.003）和 CH4 在产生的气体中的比例 （24.5%;P < 0.001）。在实验 2 中，通过饮水摄入较低量 Agolin 的公牛的 CH4 产量比实验减少了 16.4% （P = 0.0027），从第 1 周的 140 g/d 下降到第 8 周的 117 g/d。与对照阉牛相比，饮用水中 Agolin 的这种掺入率还导致阉牛的 CH4/d 排放量减少了 25 克 （17.6%） （P = 0.0205）。 然而，在处理之间，未观察到阉牛的 CH4 产量 （g CH4/kg 干物质摄入量） 或 CH4 强度 （g CH4/kg LWG） 的显著差异。这些结果表明，在体外和体内条件下，Agolin 与水溶液混合时，可减少 CH4 排放，为在粗放生产系统中减少牛的肠道 CH4 排放提供了一种潜在的方法。