College of Animal Science and Technology, Gansu Agriculture University, Lanzhou, 730070, China.
College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
BMC Microbiol. 2019 Feb 4;19(1):30. doi: 10.1186/s12866-019-1400-3.
Essential Oils (EO) are complex mixtures of plant secondary metabolites that have been proposed as promising feed additives for mitigating methane and ammonia emissions. We have previously demonstrated that Essential Oil-Cobalt (EOC) supplementation resulted in increased average daily gain and improved phenotypes (cashmere fiber traits, carcass weight, and meat quality) when cashmere goats received supplementation at approximately 2 mg/kg of body weight. However, the ruminal microbiological effects of EO remain poorly understood with regard to the extent to which ruminal populations can adapt to EO presence as feed ingredients. The effects of varying levels of EO require additional study.
In this study, we conducted metagenomic analyses using ruminal fluid samples from three groups (addition of 0, 52, and 91 mg) to evaluate the influence of dietary EOC supplementation on goat rumen bacterial community dynamics. EOC addition resulted in changes of ruminal fermentation types and the EOC dose strongly impacted the stability of ruminal microbiota. The Bacteroides sp. and Succinivibrio sp. type bacterial community was positively associated with improved volatile fatty acid production when the diet was supplemented with EOC.
A clear pattern was found that reflected rapid fermentative improvement in the rumen, subsequent to butyrate metabolism and EOC based feed additives may affect rumen microbes to further improve feed conversion. This observation indicates that EOC can be safely used to enhance animal productivity and to reduce ammonia and waste gas emissions, thus positively impacting the environment.
精油（EO）是植物次生代谢物的复杂混合物，被提议作为有前途的饲料添加剂，以减轻甲烷和氨气排放。我们之前已经证明，当绒山羊的补充剂量约为体重的 2mg/kg 时，精油-钴（EOC）补充剂可提高平均日增重并改善表型（羊绒纤维特性、胴体重和肉质）。然而，精油对瘤胃微生物的影响在多大程度上可以适应作为饲料成分的精油存在，仍知之甚少。精油的不同水平的影响需要进一步研究。
在这项研究中，我们使用来自三个组（添加 0、52 和 91mg）的瘤胃液样本进行宏基因组分析，以评估日粮 EOC 补充对山羊瘤胃细菌群落动态的影响。EOC 添加导致瘤胃发酵类型发生变化，EOC 剂量强烈影响瘤胃微生物群的稳定性。当饲料中添加 EOC 时，拟杆菌属和琥珀酸弧菌属的细菌群落与挥发性脂肪酸产量的改善呈正相关。
发现了一种清晰的模式，反映了瘤胃快速发酵的改善，随后是丁酸代谢和基于 EOC 的饲料添加剂可能会影响瘤胃微生物，以进一步提高饲料转化率。这一观察表明，EOC 可以安全地用于提高动物生产力和减少氨气和废气排放，从而对环境产生积极影响。
