摘要
BackgroundBackgrounding (BKG), the stage between weaning and finishing, significantly impacts feedlot performance in beef cattle; however, the contributions of the rumen microbiome to this growth stage remain unexplored. A longitudinal study was designed to assess how BKG affects rumen bacterial communities and average daily gain (ADG) in beef cattle. At weaning, 38 calves were randomly assigned to three BKG systems for 55 days (d): a high roughage diet within a dry lot (DL, n = 13); annual cover crop within a strip plot (CC, n = 13); and perennial pasture vegetation within rotational paddocks (PP, n = 12), as before weaning. After BKG, all calves were placed in a feedlot for 142 d and finished with a high energy ration. Calves were weighed periodically from weaning to finishing to determine ADG. Rumen bacterial communities were profiled by collecting fluid samples via oral probe and sequencing the V4 region of the 16S rRNA bacterial gene, at weaning, during BKG and finishing.ResultsRumen bacterial communities diverged drastically among calves once they were placed in each BKG system, including sharp decreases in alpha diversity for CC and DL calves only (P < 0.001). During BKG, DL calves showed a substantial increase of Proteobacteria (Succinivibrionaceae family) (P < 0.001), which also corresponded with greater ADG (P < 0.05). At the finishing stage, Proteobacteria bloomed for all calves, with no previous alpha or beta diversity differences being retained between groups. However, at finishing, PP calves showed a compensatory ADG, particularly greater than that in calves coming from DL BKG (P = 0.02). Microbiome network traits such as lower average shortest path length, and increased neighbor connectivity, degree, number and strength of bacterial interactions between rumen bacteria better predicted ADG during BKG and finishing than variation in specific taxonomic profiles.ConclusionsBacterial co-abundance interactions, as measured by network theory approaches, better predicted growth performance in beef cattle during BKG and finishing, than the abundance of specific taxa. These findings underscore the importance of early post weaning stages as potential targets for feeding interventions that can enhance metabolic interactions between rumen bacteria, to increase productive performance in beef cattle.
摘要译文
背景背景（BKG）是断奶和饰面之间的阶段，会显着影响肉牛的饲养场表现；但是，瘤胃微生物组对这个增长阶段的贡献尚未得到探索。一项纵向研究旨在评估BKG如何影响牛奶中瘤胃细菌群落和平均每日增益（ADG）。在断奶中，将38个犊牛随机分配到三个BKG系统55天（d）：干燥地块中的高粗饮食（DL，n = 13）；剥离图中的年度覆盖作物（CC，n = 13）;与断奶之前一样，旋转围场中的多年生牧场植被（pp，n = 12）。 BKG之后，将所有犊牛放在饲养场中142 d，并以高能量评分完成。从断奶到完成以确定ADG，定期称重犊牛。通过口头探针收集液体样品并测序16S rRNA细菌基因的V4区域，在断奶，BKG和整理过程中对瘤胃细菌群落进行了测序。累积的细菌群落在每个BKG系统中，包括小牛在包括每个BKG系统中，在包括每个BKG系统中差异很大，仅CC和DL犊牛的α多样性降低（p <0.001）。在BKG期间，DL犊牛显示出蛋白杆菌的大幅增加（琥珀纤维科家族）（p <0.001），这也与更大的ADG相对应（P <0.05）。在终点阶段，蛋白细菌为所有犊牛开花，在组之间没有以前的α或β多样性差异。然而，在完成时，PP犊牛显示出代偿性ADG，尤其比来自DL BKG的小牛（p = 0.02）大。微生物组网络特征，例如较低的平均路径长度较低，并增加了瘤瘤细菌之间细菌相互作用的邻居连通性，程度，数量和强度，而不是特定的分类学特征中更好的预测ADG和饰面。网络理论的方法是，比大量的特定分类单元在BKG和精加工期间更好地预测肉牛的增长性能。这些发现强调了早期断奶阶段的重要性，这是可以增强瘤胃细菌之间代谢相互作用的喂养干预措施的潜在目标，以提高牛奶中的生产性能。
Omontese; Bobwealth O.[1];Sharma; Ashok K.[1];Davison; Samuel[1];Jacobson; Emily[1];DiConstanzo; Alfredo[1];Webb; Megan J.[1];Gomez; Andres[1]. Microbiome network traits in the rumen predict average daily gain in beef cattle under different backgrounding systems[J]. Animal Microbiome, 2022,4(1): 1-15