选择了八种瘤胃添加剂进行肠甲烷缓解比较研究,包括大蒜油(GO),硝酸盐,夜蛾(AN),天门冬(ASP),植物乳杆菌(LAB),壳聚糖(CHI),精油(EOs)和3-硝基氧基丙醇(3-NOP)。使用荟萃分析方法对选定的饲料添加剂进行剂量依赖性分析,以确定在活体受试者中的有效性或在活体动物试验中的潜在功效,并特别注意肠道气体。挥发性脂肪酸浓度,和瘤胃微生物计数。所有涉及添加剂GO的荟萃分析,硝酸盐,实验室,CHI,EO,3-NOP显示甲烷产量减少,而对AN和ASP的个别研究显示瘤胃细菌群落改善和肠道CH4减少。用GO和AN补充观察到瘤胃原生动物抑制,以及用GO增加丙酸盐产量,实验室,ASP,CHI,和3-NOP瘤胃液接种。GO,AN,ASP,和LAB在体外证明了作为饲料添加剂改善瘤胃功能和充当肠甲烷缓解剂的机制。与精油商业产品相比,酶抑制剂3-NOP显示出最大的体内CH4减轻能力。此外,这项荟萃分析研究表明,体外研究显示,这些化合物的甲烷缓解水平高于体内观察到的水平,强调体内试验对最终验证使用的重要性。虽然体外产气系统可以合理准确地预测体内甲烷的生产和发酵趋势,在实际应用之前,有必要确认饲料添加剂对体内瘤胃的影响。
Eight rumen additives were chosen for an enteric methane-mitigating comparison study including garlic oil (GO), nitrate, Ascophyllum nodosum (AN), Asparagopsis (ASP), Lactobacillus plantarum (LAB), chitosan (CHI), essential oils (EOs) and 3-nitrooxypropanol (3-NOP). Dose-dependent analysis was carried out on selected feed additives using a meta-analysis approach to determine effectiveness in live subjects or potential efficacy in live animal trials with particular attention given to enteric gas, volatile fatty acid concentrations, and rumen microbial counts. All meta-analysis involving additives GO, nitrates, LAB, CHI, EOs, and 3-NOP revealed a reduction in methane production, while individual studies for AN and ASP displayed ruminal bacterial community improvement and a reduction in enteric CH4. Rumen protozoal depression was observed with GO and AN supplementation as well as an increase in propionate production with GO, LAB, ASP, CHI, and 3-NOP rumen fluid inoculation. GO, AN, ASP, and LAB demonstrated mechanisms in vitro as feed additives to improve rumen function and act as enteric methane mitigators. Enzyme inhibitor 3-NOP displays the greatest in vivo CH4 mitigating capabilities compared to essential oil commercial products. Furthermore, this meta-analysis study revealed that in vitro studies in general displayed a greater level of methane mitigation with these compounds than was seen in vivo, emphasising the importance of in vivo trials for final verification of use. While in vitro gas production systems predict in vivo methane production and fermentation trends with reasonable accuracy, it is necessary to confirm feed additive rumen influence in vivo before practical application.