摘要
The objective of this study was to explore the relationships between ruminal microbial populations from Angus steers that were divergent in carcass traits related to adipose accumulation. Twenty-four feedlot-finished Angus steers (age: 538 ± 21 d; body weight following lairage: 593.9 ± 43.7 kg) were slaughtered, and ruminal contents and carcass data were collected. Ruminal microbial deoxyribonucleic acid (DNA) extraction and 16S ribosomal ribonucleic acid (rRNA) gene sequencing were performed to determine microbial relative abundances, to estimate microbial diversity, and to predict microbial metabolic pathways. A variety of correlation analyses and one-way ANOVA were performed to investigate the relationships between the rumen microbiome and carcass traits. Marbling score (P = 0.001) and longissimus lipid content (P = 0.009) were positively correlated to Chao1 Richness Index, suggesting that increased intramuscular fat was associated with increased numbers of ruminal microbial species. The phyla Tenericutes and TM7 were negatively correlated (P ≤ 0.05) to marbling score and longissimus lipid content, indicating that lower abundances of these phyla may be associated with improvements in intramuscular fat content. Greater abundance of the bacterial family S24-7 was positively correlated (P = 0.002) to marbling score. Analysis by marbling classification revealed further linkages to microbial richness (P ≤ 0.063), diversity (P = 0.044), and S24-7 (P P ≥ 0.05) in metabolic pathway expression in rumen microbes between steers in the high- and low-marbling classes. Several phyla, families, and genera were positively correlated (P ≤ 0.05) to both rib fat thickness and yield grade. Collectively, our results suggest that microbial composition is associated to differing performance in carcass adipose traits. Overall, most of the bacterial taxa correlated to the intramuscular and subcutaneous fat depots did not overlap, suggesting the microbial population end products likely impacted adipose accumulation largely via separate adipogenic pathways of the host animal.
摘要译文
这项研究的目的是探讨来自与脂肪积累有关的car体性状不同的安格斯牛的瘤胃微生物种群之间的关系。二十四只饲养场完成的安格斯牛（年龄：538±21 d；屠宰后体重：593.9±43.7 kg），收集了瘤胃内容物和car体数据。进行了瘤胃微生物脱氧核糖核酸（DNA）提取和16S核糖体核糖核酸（rRNA）基因测序，以确定微生物的相对丰度，评估微生物的多样性，并预测微生物的代谢途径。进行了各种相关分析和单向方差分析，以研究瘤胃微生物组与car体性状之间的关系。大理石花纹得分（P = 0.001）和背最长肌脂质含量（P = 0.009）与Chao1丰富度指数呈正相关，表明肌肉内脂肪增加与瘤胃微生物种类增加有关。 Teneracutes和TM7的门与大理石花纹得分和加长的脂血含量呈负相关（P≤0.05），表明这些门的较低丰度可能与肌肉内脂肪含量的改善有关。细菌家族S24-7的丰富度与大理石花纹得分呈正相关（P = 0.002）。大理石花纹分类的分析显示，高大理石花纹和低大理石花纹的ste牛皮之间的瘤胃微生物代谢途径表达与微生物丰富度（P≤0.063），多样性（P = 0.044）和S24-7（PP≥0.05）进一步相关。 。几个门，科和属与肋骨脂肪厚度和产量等级呈正相关（P≤0.05）。总的来说，我们的结果表明，微生物组成与car体脂肪性状的不同表现有关。总体而言，与肌肉内和皮下脂肪库相关的大多数细菌类群并没有重叠，这表明微生物种群的最终产物很可能主要通过宿主动物的成脂途径而影响了脂肪的积累。
Taylor R Krause [1]; Jeferson M Lourenco [1]; Christina B Welch [1]; Michael J Rothrock [2]; Todd R Callaway [1]; T Dean Pringle [1]. The relationship between the rumen microbiome and carcass merit in Angus steers[J]. Journal of Animal Science, 2020,98(9)