Dietary energy sources and levels shift the multi-kingdom microbiota and functions in the rumen of lactating dairy cows
Dietary energy sources and levels shift the multi-kingdom microbiota and functions in the rumen of lactating dairy cows
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DOI：
10.1186/s40104-020-00461-2
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发表时间：
2020-06-22
影响因子：
7
通讯作者：
Yu, Zhongtang
中科院分区：
文献类型：
--
作者：
Park, Tansol;Ma, Lu;Yu, Zhongtang
背景哺乳期日粮能量来源和水平对产奶量和乳成分有重要影响。这种对泌乳性能的饮食影响是由瘤胃微生物群的改变所支撑的，其中细菌、古细菌、真菌和原生动物可能不同。然而，很少有研究检查所有四组瘤胃微生物。本试验研究了日粮能量水平和能量来源对泌乳奶牛瘤胃细菌、古菌、真菌和原虫的影响。2 × 2析因设计产生四种膳食处理：低和高膳食能量水平（LE：1.52 - 1.53;和HE：1.71 - 1.72 Mcal/kg干物质）和两种膳食能量来源（GC：细磨玉米;和SFC：蒸汽压片玉米）。试验采用4 × 4拉丁方重复设计，选用8头经产中国荷斯坦奶牛，每个周期为21 d。使用基于王国特异性系统发育标记[细菌和古细菌的16S rRNA基因，原生动物的18S rRNA基因和真菌的内部转录间隔区1（ITS1）]的元分类学分析瘤胃微生物群，随后使用PICRUSt2进行功能预测。结果GC组的原核生物（细菌和古细菌）物种丰富度和Faith系统发育多样性高于SFC组。对于真核生物（真菌和原生动物）微生物群，LE组的上述测量值显著高于HE组。在主要分类类群中，23个属在所有的王国不同的相对丰度之间的两种饮食能量水平，而只有6个属（没有原生动物）的差异丰富的两种能源之间。基于来自所有样品的原核扩增子序列变体（ASV），使用PICRUSt2预测的总体功能谱在LE和HE之间显著不同，但在两种能量来源之间不显著。FishTaco分析鉴定出瘤胃球菌和粪球菌为可能有助于富集KEGG途径的类群，该途径用于氨基酸的生物合成以及丙酮酸盐、甘油磷脂、烟酸盐和烟酰胺在HE饲喂奶牛的瘤胃中的代谢。共现网络也受到饮食处理的影响，特别是LE和GC饮食，导致不同的共现网络。几个微生物属似乎与一个或多个泌乳性状密切相关。结论日粮能量水平影响瘤胃微生物菌群，而玉米粉和蒸汽压片玉米差异不大。一些属也受到不同的影响，由四个饮食治疗，包括属已被证明与泌乳性能或饲料效率。专为每种饮食处理发现的属之间的共现模式可能表明可能的代谢相互作用特别受饮食处理的影响。一些主要类群与牛奶的性质呈正相关，并可能作为一个或多个泌乳性状的生物标志物。
Background Dietary energy source and level in lactation diets can profoundly affect milk yield and composition. Such dietary effects on lactation performance are underpinned by alteration of the rumen microbiota, of which bacteria, archaea, fungi, and protozoa may vary differently. However, few studies have examined all the four groups of rumen microbes. This study investigated the effect of both the level and source of dietary energy on rumen bacteria, archaea, fungi, and protozoa in the rumen of lactating dairy cows. A 2 x 2 factorial design resulted in four dietary treatments: low and high dietary energy levels (LE: 1.52-1.53; and HE: 1.71-1.72 Mcal/kg dry matter) and two dietary energy sources (GC: finely ground corn; and SFC: steam-flaked corn). We used a replicated 4 x 4 Latin square design using eight primiparous Chinese Holstein cows with each period lasting for 21 d. The rumen microbiota was analyzed using metataxonomics based on kingdom-specific phylogenetic markers [16S rRNA gene for bacteria and archaea, 18S rRNA gene for protozoa, and internally transcribed spacer 1 (ITS1) for fungi] followed with subsequent functional prediction using PICRUSt2. Results The GC resulted in a higher prokaryotic (bacterial and archaeal) species richness and Faith's phylogenetic diversity than SFC. For the eukaryotic (fungi and protozoa) microbiota, the LE diets led to significantly higher values of the above measurements than the HE diets. Among the major classified taxa, 23 genera across all the kingdoms differed in relative abundance between the two dietary energy levels, while only six genera (none being protozoal) were differentially abundant between the two energy sources. Based on prokaryotic amplicon sequence variants (ASVs) from all the samples, overall functional profiles predicted using PICRUSt2 differed significantly between LE and HE but not between the two energy sources. FishTaco analysis identifiedRuminococcusandCoprococcusas the taxa potentially contributing to the enriched KEGG pathways for biosynthesis of amino acids and to the metabolisms of pyruvate, glycerophospholipid, and nicotinate and nicotinamide in the rumen of HE-fed cows. The co-occurrence networks were also affected by the dietary treatments, especially the LE and GC diets, resulting in distinct co-occurrence networks. Several microbial genera appeared to be strongly correlated with one or more lactation traits. Conclusions Dietary energy level affected the overall rumen multi-kingdom microbiota while little difference was noted between ground corn and steam-flaked corn. Some genera were also affected differently by the four dietary treatments, including genera that had been shown to be correlated with lactation performance or feed efficiency. The co-occurrence patterns among the genera exclusively found for each dietary treatment may suggest possible metabolic interactions specifically affected by the dietary treatment. Some of the major taxa were positively correlated to milk properties and may potentially serve as biomarkers of one or more lactation traits.