Institute of Animal Nutrition, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Bundesallee 37, 38116 Brunswick, Germany; Clinic for Ruminants and Swine, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 11, 04103 Leipzig, Germany.
Institute of Animal Nutrition, Friedrich-Loeffler-Institut (FLI), Federal Research Institute for Animal Health, Bundesallee 37, 38116 Brunswick, Germany.
J Dairy Sci. 2018 May;101(5):4615-4637. doi: 10.3168/jds.2017-13736. Epub 2018 Feb 15.
Different studies have shown a strong correlation between the rumen microbiome and a range of production traits (e.g., feed efficiency, milk yield and components) in dairy cows. Underlying dynamics concerning cause and effect are, however, still widely unknown and warrant further investigation. The aim of the current study was to describe possible functional interrelations and pathways using a large set of variables describing the production, the metabolic and immunological state, as well as the rumen microbiome and fermentation characteristics of dairy cows in early lactation (n = 36, 56 ± 3 d in milk). It was further hypothesized that the feed intake-associated behavior may influence the ruminal fermentation pattern, and a set of variables describing these individual animal attributes was included. Principal component analysis as well as Spearman's rank correlations were conducted including a total of 265 variables. The attained plots describe several well-known associations between metabolic, immunological, and production traits. Main drivers of variance within the data set included milk production and efficiency as well as rumen fermentation and microbiome diversity attributes, whereas behavioral, metabolic, and immunological variables did not exhibit any strong interrelations with the other variables. The previously well-documented strong correlation of production traits with distinct prokaryote groups was confirmed. This mainly included a negative correlation of operational taxonomic units ascribed to the Prevotella genus with milk and fat yield and feed efficiency. A central role of the animals' feed intake behavior in this context could not be affirmed. Furthermore, different methodological and interpretability aspects concerning the microbiome analysis by 16S rRNA gene sequencing, such as the discrepancy between taxonomic classification and functional communality, as well as the comparability with other studies, are discussed. We concluded that, to further investigate the driving force that causes the difference between efficient and inefficient animals, studies including more sophisticated methods to describe phenotypical traits of the host (e.g., rumen physiology, metabolic and genetic aspects) as well as the rumen microbiome (e.g., metagenome, metatranscriptome, metaproteome, and metabolome analysis) are needed.
不同的研究表明瘤胃微生物组与奶牛的一系列生产性状（例如饲料效率、产奶量和成分）之间存在很强的相关性。然而，关于因果关系的潜在动态仍然知之甚少，需要进一步研究。本研究的目的是使用大量描述生产、代谢和免疫状态以及奶牛瘤胃微生物组和发酵特性的变量来描述可能的功能相互关系和途径，这些变量在泌乳早期（n = 36，泌乳 56 ± 3 d）。进一步假设与采食量相关的行为可能会影响瘤胃发酵模式，并纳入了一组描述这些个体动物属性的变量。进行了主成分分析和 Spearman 秩相关分析，共包括 265 个变量。获得的图谱描述了代谢、免疫和生产性状之间的一些众所周知的关联。该数据集内方差的主要驱动因素包括产奶量和效率以及瘤胃发酵和微生物多样性属性，而行为、代谢和免疫变量与其他变量之间没有任何强烈的相互关系。先前记录的生产性状与特定原核生物群之间的强相关性得到了证实。这主要包括归属于普雷沃氏菌属的操作分类单元与产奶量和脂肪产量以及饲料效率呈负相关。动物的采食量行为在这种情况下不能被肯定。此外，还讨论了 16S rRNA 基因测序微生物组分析的不同方法和可解释性方面，例如分类学分类与功能共性之间的差异以及与其他研究的可比性。我们得出结论，为了进一步研究导致高效和低效动物之间差异的驱动力，需要进行包括更复杂的方法来描述宿主（例如瘤胃生理学、代谢和遗传方面）以及瘤胃微生物组（例如宏基因组、宏转录组、宏蛋白质组和代谢组分析）的表型特征的研究。
