Welch Christina Breanne, Lourenco Jeferson M, Seidel Darren S, Krause Taylor Rae, Rothrock Michael J, Pringle T Dean, Callaway Todd R
Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602, USA.
Egg Safety and Quality Research Unit, Richard B. Russell Research Center, Agricultural Research Service, USDA, Athens, GA 30605, USA.
Microorganisms. 2021 Dec 19;9(12):2625. doi: 10.3390/microorganisms9122625.
Diet impacts the composition of the ruminal microbiota; however, prior to slaughter, cattle are fasted, which may change the ruminal microbial ecosystem structure and lead to dysbiosis. The objective of this study was to determine changes occurring in the rumen after pre-slaughter fasting, which can allow harmful pathogens an opportunity to establish in the rumen. Ruminal samples were collected before and after pre-slaughter fasting from seventeen commercial Angus steers. DNA extraction and 16S rRNA gene sequencing were performed to determine the ruminal microbiota, as well as volatile fatty acid (VFA) concentrations. Microbial richness (Chao 1 index), evenness, and Shannon diversity index all increased after fasting ( ≤ 0.040). During fasting, the two predominant families and decreased ( ≤ 0.029), whereas the remaining minor families increased ( < 0.001). Fasting increased and ( ≤ 0.003), while and tended to increase ( ≤ 0.086). Butyrate concentration tended to decrease ( = 0.068) after fasting. The present findings support that fasting causes ruminal nutrient depletion resulting in dysbiosis, allowing opportunistic pathogens to exploit the void in the ruminal ecological niche.
饮食会影响瘤胃微生物群的组成；然而，在屠宰前，牛会禁食，这可能会改变瘤胃微生物生态系统结构并导致菌群失调。本研究的目的是确定屠宰前禁食后瘤胃中发生的变化，这可能会让有害病原体有机会在瘤胃中定植。从17头商业安格斯阉牛身上在屠宰前禁食前后采集瘤胃样本。进行DNA提取和16S rRNA基因测序以确定瘤胃微生物群以及挥发性脂肪酸（VFA）浓度。禁食后微生物丰富度（Chao 1指数）、均匀度和香农多样性指数均增加（≤0.040）。在禁食期间，两个主要菌科和减少（≤0.029），而其余次要菌科增加（<0.001）。禁食增加了和（≤0.003），而和趋于增加（≤0.086）。禁食后丁酸盐浓度趋于降低（=0.068）。目前的研究结果支持禁食会导致瘤胃营养物质耗尽，从而导致菌群失调，使机会性病原体利用瘤胃生态位中的空缺。
