摘要
Our previous study suggested that supplementation of high-grain diets with ruminally protected and non-protected active dried yeast (ADY) may potentially reduce manure pathogen excretion by feedlot cattle. We hypothesized that feeding ruminally protected ADY might change the fecal bacterial community of finishing cattle. The objective of this study was to investigate the effects of feeding ruminally protected and non-protected ADY to finishing beef steers on their fecal bacterial community. Fresh fecal samples were collected on day 56 from 50 steers fed one of five treatments: 1) control (no monensin, tylosin, or ADY), 2) antibiotics (ANT, 330 mg monensin + 110 mg tylosin·steer−1d−1), 3) ADY (1.5 g·steer−1d−1), 4) encapsulated ADY (EDY; 3 g·steer−1d−1), and 5) a mixture of ADY and EDY (MDY; 1.5 g ADY + 3 g EDY·steer−1d−1). Bacterial DNA was extracted from fecal samples and sequenced using a MiSeq high-throughput sequencing platform. A total number of 2,128,772 high-quality V4 16S rRNA sequences from 50 fecal samples were analyzed, and 1,424 operational taxonomic units (OTU) were detected based on 97% nucleotide sequence identity among reads, with 769 OTU shared across the five treatments. Alpha diversity indices, including species observed, Chao estimate, abundance-based coverage estimator, Shannon, Simpson, and coverage, did not differ among treatments, and principal coordinate analysis revealed a high similarity among treatments without independent distribution. Bacteroidetes and Firmicutes were dominant phyla in the fecal bacterial community for all treatments, with a tendency (P < 0.10) for greater relative abundance of Bacteroidetes but lesser Firmicutes with ANT, EDY, and MDY compared with control steers. Prevotella was the dominant genus in all treatments and steers supplemented with ANT, EDY, and MDY had greater (P < 0.05) relative abundance of Prevotella than control steers, but lesser (P < 0.03) relative abundance of Oscillospira. No differences between ADY and control were observed for the aforementioned variables. Fecal starch contents were not different among treatments, but the relative abundance of Bacteroidetes, as well as Prevotella at genera level, tended (P < 0.06) to be positively correlated to fecal starch content. We conclude that supplementing ruminally protected or non-protected ADY or ANT had no effect on diversity and richness of fecal bacteria of finishing beef cattle, whereas feeding protected ADY or ANT to finishing beef steers altered the dominant fecal bacteria at phylum and genus levels. Therefore, supplementation of ruminally protected ADY may potentially improve intestinal health by stimulating the relative abundance of Prevotella.
摘要译文
我们以前的研究表明，在高谷物饮食中添加反刍动物保护和非保护性活性干酵母（ADY）可能会减少饲养场牛粪便病原体的排泄。我们假设饲喂受瘤胃保护的ADY可能会改变育肥牛的粪便细菌群落。这项研究的目的是研究饲喂瘤胃保护的和未保护的ADY对肥牛公牛的粪便细菌群落的影响。在第56天从五种处理之一的50头ste牛中采集新鲜粪便样本：1）对照（无莫能菌素，泰乐菌素或ADY），2）抗生素（ANT，330毫克莫能菌素+ 110毫克泰乐菌素·转向<-1） d −1 ），3）ADY（1.5 g·steer -1 d -1 ），4）封装的ADY（ EDY; 3 g·steer -1 d -1 ），和5）ADY和EDY（MDY）的混合物。 1.5 g ADY + 3 g EDY·steer -1 d -1 ）。从粪便样本中提取细菌DNA，并使用MiSeq高通量测序平台进行测序。分析了50个粪便样品中的2,128,772个高质量V4 16S rRNA序列，基于读段中97％的核苷酸序列同一性，检测到1,424个操作分类单位（OTU），在五个处理中共有769个OTU。 Alpha多样性指数（包括观察到的物种，Chao估计值，基于丰度的覆盖率估算器，Shannon，Simpson和覆盖率）在处理之间没有差异，并且主坐标分析显示，在没有独立分布的处理之间存在高度相似性。在所有处理中，拟杆菌和硬毛菌是粪细菌群落中的主要菌群，与对照转向相比，拟杆菌的相对丰度更高（P <0.10），而蚂蚁，EDY和MDY的菌毛较少。 Prevotella是所有处理中的主要属，添加ANT，EDY和MDY的公牛的Prevotella相对丰度比对照公牛要高（P <0.05），但相对于Oscillospira则要小（P <0.03）。对于上述变量，在ADY和对照之间未观察到差异。粪便中淀粉的含量在各处理之间没有差异，但拟杆菌属的相对丰度以及属属水平上的普氏杆菌倾向于与粪便中的淀粉含量呈正相关（P <0.06）。我们得出的结论是，添加反刍动物保护的或未保护的ADY或ANT对肥育牛的粪便细菌的多样性和丰富度没有影响，而将受保护的ADY或ANT饲喂肥育牛的粪便会改变门类和属水平的主要粪便细菌。因此，补充反刍动物保护的ADY可能会通过刺激Prevotella的相对丰度来改善肠道健康。
Tao Ran [1]; Peixin Jiao [2]; Ousama AlZahal [3]; Xiaolai Xie [4]; Karen A Beauchemin [1]; Dongyan Niu [4]; Wenzhu Yang [1]. Fecal bacterial community of finishing beef steers fed ruminally protected and non-protected active dried yeast[J]. Journal of Animal Science, 2020,98(4)