摘要
To assess the effects of residual feed intake (RFI) and breed on rumen microbiota, the abundance (DNA) and active population (RNA) of the total bacteria, archaea, protozoa, and fungi in the rumen of 96 beef steers from three different breeds (Angus (AN), Charolais (CH), and Kinsella Composite (KC)), and divergent RFIs (High vs Low), were estimated by measuring their respective maker gene copies using qRT-PCR. All experimental animals were kept under the same feedlot condition and fed with the same high-energy finishing diet. Rumen content samples were collected at slaughter and used for the extraction of genetic material (DNA and RNA) and further analysis. There was a significant difference (p < 0.01) between the marker gene copies detected for abundance and active populations for all four microbial groups. AN steers had a higher abundance of bacteria (p < 0.05) and a lower abundance of eukaryotes (protozoa and fungi, p < 0.05) compared to KC steers, while the abundance of protozoa (p < 0.05) in the AN cattle and fungi (p < 0.05) in the KC cattle were lower and higher, respectively, than those in the CH steers. Meanwhile, the active populations of bacteria, archaea, and protozoa in the KC steers were significantly lower than those in the AN and CH animals (p < 0.01). This work demonstrates that cattle breed can affect rumen microbiota at both the abundance and activity level. The revealed highly active protozoal populations indicate their important role in rumen microbial fermentation under a feedlot diet, which warrants further study.
摘要译文
评估残留饲料摄入量（RFI）和繁殖对瘤胃微生物群的影响，总细菌，古细菌，原生动物和真菌的丰度（DNA）和活性种群（RNA）在来自三种不同品种的96牛肉中（Angus（An），Charolais（CH）和Kinsella Composite（KC））和Divergent RFI（高vs Low）通过使用QRT-PCR测量其各自的Make基因拷贝来估算。所有实验动物均处于相同的饲养场状态，并以相同的高能量精加工饮食喂养。在屠宰时收集瘤胃含量样品，并用于提取遗传材料（DNA和RNA）和进一步分析。在所有四个微生物基团的丰度和活性种群中检测到的标记基因拷贝之间存在显着差异（p <0.01）。与KC牛头相比，蒸汽的细菌丰度更高（p <0.05）和较低的真核生物（原生动物和真菌，p <0.05），而在牛和真菌中的原生动物（p <0.05）（p <0.05）（p <0.05）（p <0.05）（ KC牛中的p <0.05）分别较低和更高。同时，KC龙骨中细菌，古细菌和原生动物的活性群体明显低于AN和CH动物中的细菌（P <0.01）。这项工作表明，牛品种在丰度和活动水平上都会影响瘤胃菌群。揭示的高度活跃的原生动物人群表明，在饲养场饮食下，它们在瘤胃微生物发酵中的重要作用，这需要进一步研究。
Yawei Zhang;Fuyong Li;Yanhong Chen;Le-Luo Guan. The Effects of Breed and Residual Feed Intake Divergence on the Abundance and Active Population of Rumen Microbiota in Beef Cattle[J]. Animals, 2022,12(15): 1966