Methane production and fatty acids (FA) biohydrogenation in the rumen are two main constraints in ruminant production causing environmental burden and reducing food product quality. Rumen functions can be modulated by the biologically active compounds (BACs) of plant origins as shown in several studies e.g. reduction in methane emission, modulation of FA composition with positive impact on the ruminant products. Coleus amboinicus Lour. (CAL) contains high concentration of polyphenols that may potentially reduce methane production and modulate ruminal biohydrogenation of unsaturated FA. This study aimed to investigate the effect of BAC of Coleus amboinicus Lour. (CAL) fed to growing lambs on ruminal methane production, biohydrogenation of unsaturated FA and meat characteristics. In this study, the in vitro experiment aiming at determining the most effective CAL dose for in vivo experiments was followed by two in vivo experiments in rumen-cannulated rams and growing lambs. Experiment 1 (RUSITEC) comprised of control and three experimental diets differing in CAL content (10%, 15%, and 20% of the total diet). The two in vivo experiments were conducted on six growing, rumen-cannulated lambs (Exp. 2) and 16 growing lambs (Exp. 3). Animals were assigned into the control (CON) and experimental (20% of CAL) groups. Several parameters were examined in vitro (pH, ammonia and VFA concentrations, protozoa, methanogens and select bacteria populations) and in vivo (methane production, digestibility, ruminal microorganism populations, meat quality, fatty acids profiles in rumen fluid and meat, transcript expression of 5 genes in meat). CAL lowered in vitro methane production by 51%. In the in vivo Exp. 3, CAL decreased methane production by 20% compared with the CON group, which corresponded to reduction of total methanogen counts by up to 28% in all experiments, notably Methanobacteriales. In Exp. 3, CAL increased or tended to increase populations of some rumen bacteria (Ruminococcus albus, Megasphaera elsdenii, Butyrivibrio proteoclasticus, and Butyrivibrio fibrisolvens). Dietary CAL suppressed the Holotricha population, but increased or tended to increase Entodiniomorpha population in vivo. An increase in the polyunsaturated fatty acid (PUFA) proportion in the rumen of lambs was noted in response to the CAL diet, which was mainly attributable to the increase in C18:3 cis-9 cis-12 cis-15 (LNA) proportion. CAL reduced the mRNA expression of four out of five genes investigated in meat (fatty acid synthase, stearoyl-CoA desaturase, lipoprotein lipase, and fatty acid desaturase 1). Summarizing, polyphenols of CAL origin (20% in diet) mitigated ruminal methane production by inhibiting the methanogen communities. CAL supplementation also improved ruminal environment by modulating ruminal bacteria involved in fermentation and biohydrogenation of FA. Besides, CAL elevated the LNA concentration, which improved meat quality through increased deposition of n-3 PUFA. • Coleus amboinicus Lour. (CAL) into sheep diet decreased CH4 emission. • CAL did not reduce nutrient digestibility, but inhibited the methanogen community. • CAL increased ruminal propionate proportion and decreased acetate/propionate ratio. • CAL elevated n-3 fatty acid concentration in ruminal fluid and meat. • Supplementation of CAL improved some meat quality traits.

中文翻译：

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饮食锦紫苏 Lour。减少瘤胃产甲烷和生物氢化，改善羔羊胸最长肌的肉质和脂肪酸组成

瘤胃中的甲烷产生和脂肪酸 (FA) 生物加氢是反刍动物生产中的两个主要限制因素，造成环境负担和降低食品质量。瘤胃功能可以通过植物来源的生物活性化合物 (BAC) 来调节，如几项研究所示，例如减少甲烷排放、调节 FA 成分对反刍动物产品产生积极影响。锦紫苏 Lour。(CAL) 含有高浓度的多酚，可能会减少甲烷的产生并调节瘤胃中不饱和脂肪酸的生物加氢。本研究旨在探讨锦紫苏 BAC 的作用。(CAL) 在瘤胃甲烷产生、不饱和 FA 的生物氢化和肉类特性方面饲喂正在生长的羔羊。在这项研究中，旨在确定用于体内实验的最有效 CAL 剂量的体外实验之后是在瘤胃插管公羊和生长羔羊中进行的两项体内实验。实验 1 (RUSITEC) 包括对照和三种不同 CAL 含量的实验日粮（占总日粮的 10%、15% 和 20%）。对六只生长的、瘤胃插管的羔羊（实验 2）和 16 只生长的羔羊（实验 3）进行了两次体内实验。动物被分配到对照组（CON）和实验组（20%的CAL）。在体外（pH、氨和 VFA 浓度、原生动物、产甲烷菌和选择的细菌种群）和体内（甲烷产生、消化率、瘤胃微生物种群、肉质、瘤胃液和肉中的脂肪酸谱、肉中有 5 个基因）。CAL 将体外甲烷产量降低了 51%。在体内实验中。如图 3 所示，与 CON 组相比，CAL 降低了 20% 的甲烷产量，这对应于在所有实验中总产甲烷菌数量减少了 28%，尤其是甲烷杆菌。在 Exp。3、CAL增加或倾向于增加一些瘤胃细菌（Ruminococcus albus、Megasphaera elsdenii、Butyrivibrio proteoclasticus和Butyrivibrio fibrisolvens）的数量。膳食 CAL 抑制了 Holotricha 种群，但增加或倾向于增加体内 Entodiniomorpha 种群。注意到 CAL 饮食导致羔羊瘤胃中多不饱和脂肪酸 (PUFA) 比例的增加，这主要归因于 C18:3 cis-9 cis-12 cis-15 (LNA) 比例的增加。CAL 降低了肉中研究的五种基因中的四种（脂肪酸合酶、硬脂酰辅酶 A 去饱和酶、脂蛋白脂肪酶和脂肪酸去饱和酶 1）的 mRNA 表达。总之，CAL 来源的多酚（日粮中的 20%）通过抑制产甲烷菌群落来减轻瘤胃甲烷的产生。CAL 补充剂还通过调节参与 FA 发酵和生物加氢的瘤胃细菌来改善瘤胃环境。此外，CAL 提高了 LNA 浓度，通过增加 n-3 PUFA 的沉积来改善肉质。• 锦紫苏Lour。(CAL) 喂入绵羊饲料可减少 CH4 排放。• CAL 不会降低营养物质的消化率，但会抑制产甲烷菌群落。• CAL 增加瘤胃丙酸盐比例并降低乙酸/丙酸盐比例。• CAL 提高了瘤胃液和肉中的 n-3 脂肪酸浓度。• CAL 的补充改善了一些肉质性状。