The objective of this study was to investigate the effects of origanum oil (ORO), hydrolysable tannins (HYT) and tea saponin (TES) on methane (CH₄) emission, rumen fermentation, productive performance and gas exchange in sheep by using in vitro and in vivo methods. The ORO, HYT and TES additive levels were normalized per kg dry matter (DM) in both in vitro and in vivo experiments: ORO-0, 10, 20 and 40 ml/kg; HYT-0, 15, 30 and 60 g/kg; and TES-0, 15, 30 and 60 g/kg, respectively. During in vitro incubation, 40 ml/kg ORO linearly decreased CH₄ emission (p < 0.05); 20 and 40 ml/kg ORO cubically decreased carbon dioxide (CO₂) production (p < 0.05), and rumen pH was cubically raised with the increasing ORO additive level (p < 0.01). The 60 g/kg HYT cubically decreased CH₄ production (p < 0.05). The pH of 60 g/kg HYT was higher than that of 15 and 30 g/kg (p < 0.01); the pH of 20 g/kg TES was higher than that of 5 g/kg (p < 0.05). In the in vivo experiments, 40 ml/kg ORO inhibited dry matter intake (p < 0.01) cubically and reduced average daily gain (ADG) and feed conversion ratio (FCR) cubically (p < 0.05), and 20 or 40 ml/kg ORO linearly decreased CH₄ production based on per day or metabolic weight (W^0.75) (p < 0.05). Both 30 and 60 g/kg HYT linearly inhibited CH₄ emission on the bases of per day and W^0.75 (p < 0.05). The 20 g/kg TES improved the apparent digestibility of crude protein (p < 0.05), 10 and 20 g/kg of TES decreased CH₄ emission (p < 0.05), and 5 g/kg of TES reduced O₂ consumption and CO₂ production (p < 0.05). In conclusion, these three plant extracts all showed the abilities on mitigating CH₄ emission of sheep with appropriate additive ranges.

中文翻译：

---

牛至油、可水解单宁和茶皂素在减轻反刍动物甲烷方面的评价：体外和体内方法

本研究的目的是通过体外实验研究牛至油（ORO）、可水解单宁（HYT）和茶皂素（TES）对羊甲烷（CH ₄）排放、瘤胃发酵、生产性能和气体交换的影响。和体内方法。在体外和体内实验中，ORO、HYT 和 TES 添加剂水平按每公斤干物质 (DM) 进行标准化：ORO-0、10、20 和 40 ml/kg；HYT-0、15、30 和 60 克/公斤；和 TES-0、15、30 和 60 g/kg，分别。在体外培养期间，40 ml/kg ORO 线性降低 CH ₄排放（p  < 0.05）；20 和 40 ml/kg ORO 立方减少了二氧化碳 (CO ₂ ) 产量 ( p < 0.05），并且瘤胃 pH 值随着 ORO 添加剂水平的增加而呈立方上升（p  < 0.01）。60 g/kg HYT 立方减少了 CH ₄产量（p  < 0.05）。60 g/kg HYT的pH值高于15和30 g/kg ( p  < 0.01)；20 g/kg TES 的 pH 值高于 5 g/kg ( p  < 0.05)。在体内实验中，40 ml/kg ORO 可抑制干物质摄入量 ( p  < 0.01) 立方并降低平均日增重 (ADG) 和饲料转化率 (FCR) 立方 ( p  < 0.05)，20 或 40 ml/kg ORO线性减小CH ₄以每天或代谢重量（W生产^0.75）（p < 0.05)。30 和 60 g/kg HYT 均以每天和 W ^0.75 ( p  < 0.05)为基础线性抑制 CH ₄排放。20 g/kg TES 提高了粗蛋白的表观消化率 ( p  < 0.05)，10 和 20 g/kg TES 降低了 CH ₄排放 ( p  < 0.05)，5 g/kg TES 降低了 O ₂消耗和 CO ₂产量（p  < 0.05）。综上所述，这三种植物提取物均显示出在适当的添加范围内减轻绵羊CH ₄排放的能力。