Lourenco Jeferson M, Welch Christina B, Krause Taylor R, Wieczorek Michael A, Fluharty Francis L, 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. 2022 May 31;10(6):1128. doi: 10.3390/microorganisms10061128.
The gastrointestinal microbiota of cattle is important for feedstuff degradation and feed efficiency determination. This study evaluated the fecal microbiome of Angus steers with distinct feed efficiencies during the feedlot-finishing phase. Angus steers ( = 65), fed a feedlot-finishing diet for 82 days, had growth performance metrics evaluated. Steers were ranked based upon residual feed intake (RFI), and the 5 lowest RFI (most efficient) and 5 highest RFI (least efficient) steers were selected for evaluation. Fecal samples were collected on 0-d and 82-d of the finishing period and microbial DNA was extracted and evaluated by 16S rRNA gene sequencing. During the feedlot trial, inefficient steers had decreased ( = 0.02) populations and increased ( = 0.01) populations. Conversely, efficient steers had increased ( = 0.03) and ( = 0.01), and a trend for decreased abundance ( = 0.096). Efficient steers had increased microbial richness and diversity during the feedlot period, which likely resulted in increased fiber-degrading enzymes in their hindgut, allowing them to extract more energy from the feed. Results suggest that cattle with better feed efficiency have greater diversity of hindgut microorganisms, resulting in more enzymes available for digestion, and improving energy harvest in the gut of efficient cattle.
牛的胃肠道微生物群对于饲料降解和饲料效率的测定很重要。本研究评估了在育肥期具有不同饲料效率的安格斯阉牛的粪便微生物组。65头安格斯阉牛饲喂育肥期日粮82天，并对其生长性能指标进行评估。根据剩余采食量（RFI）对阉牛进行排名，选择5头RFI最低（效率最高）和5头RFI最高（效率最低）的阉牛进行评估。在育肥期的第0天和第82天采集粪便样本，提取微生物DNA并通过16S rRNA基因测序进行评估。在育肥试验期间，效率低的阉牛 菌数量减少（P = 0.02）， 菌数量增加（P = 0.01）。相反，效率高的阉牛 菌（P = 0.03）和 菌（P = 0.01）数量增加，且 菌丰度有降低趋势（P = 0.096）。效率高的阉牛在育肥期微生物丰富度和多样性增加，这可能导致其后肠中纤维降解酶增加，使其能够从饲料中提取更多能量。结果表明，饲料效率较高的牛后肠微生物多样性更高，从而产生更多可用于消化的酶，并提高了高效牛肠道中的能量获取。
