动物的发育和生长与其微生物的建立和成熟相吻合。为了评估牛犊从出生到断奶的呼吸和粪便微生物,总共有30头怀孕的母牛,和他们出生时的小牛,参加了这项研究。纵向从小牛收集深鼻拭子和粪便,从出生那天开始,到断奶那天结束。鼻咽,阴道,还从奶牛身上收集了粪便样本,并分析了所有样品的微生物。在生命的前8周内,小牛的粪便微生物群富含乳酸菌,在被与纤维消化相关的属取代之前,然后随着时间的推移多样性增加。相比之下,小牛呼吸道微生物群的多样性一般随着年龄的增长而下降。出生时,小牛和牛鼻微生物非常相似,表明来自大坝接触的定殖。这得到了微生物来源追踪分析的支持。小牛鼻腔微生物群的结构与奶牛的结构相似,直到断奶,当它发散的时候。这些变化是由乳酸菌的减少和通常与牛呼吸道疾病相关的属的增加所驱动的。包括Mannheimia,巴斯德,和支原体。这三个属在幼年被殖民的小牛,尽管Mannheimia最初是从奶牛生殖道转移的。路径分析用于模拟小牛呼吸和粪便微生物的相互关系。观察到,呼吸道乳杆菌和粪便螺旋藻科UCG-005对Mannheimia或巴氏杆菌的丰度产生了负面影响。重要的肉牛生产,牛呼吸道疾病(BRD)占饲养场发病率和死亡率的大部分。过敏反应是缓解BRD的常用管理工具,然而,它的使用导致抗菌素耐药性增加。需要减轻BRD的新方法,包括基于微生物群的策略。然而,有关断奶前牛犊呼吸道细菌的信息有限。在这项研究中,研究表明,奶牛的微生物群影响了小牛呼吸道和粪便微生物的初始组成。虽然BRD相关属对小牛呼吸道的定殖发生在生命早期,它们的相对丰度在断奶时增加,与呼吸道和肠道细菌呈负相关。因此,呼吸道和胃肠道的微生物在对抗呼吸道病原体方面具有重要作用,是增强小腿呼吸健康的潜在靶标。调制可能是最有益的,如果在断奶前完成,在机会性病原体建立定植之前。
The development and growth of animals coincide with the establishment and maturation of their microbiotas. To evaluate the respiratory and fecal microbiotas of beef calves from birth to weaning, a total of 30 pregnant cows, and their calves at birth, were enrolled in this study. Deep nasal swabs and feces were collected from calves longitudinally, starting on the day of birth and ending on the day of weaning. Nasopharyngeal, vaginal, and fecal samples were also collected from cows, and the microbiotas of all samples were analyzed. The fecal microbiota of calves was enriched with Lactobacillus during the first 8 weeks of life, before being displaced by genera associated with fiber digestion, and then increasing in diversity across time. In contrast, the diversity of calf respiratory microbiota generally decreased with age. At birth, the calf and cow nasal microbiotas were highly similar, indicating colonization from dam contact. This was supported by microbial source-tracking analysis. The structure of the calf nasal microbiota remained similar to that of the cows, until weaning, when it diverged. The changes were driven by a decrease in Lactobacillus and an increase in genera typically associated with bovine respiratory disease, including Mannheimia, Pasteurella, and Mycoplasma. These three genera colonized calves early in life, though Mannheimia was initially transferred from the cow reproductive tract. Path analysis was used to model the interrelationships of calf respiratory and fecal microbiotas. It was observed that respiratory Lactobacillus and fecal Oscillospiraceae UCG-005 negatively affected the abundance of Mannheimia or Pasteurella.IMPORTANCEIn beef cattle production, bovine respiratory disease (BRD) accounts for most of the feedlot morbidities and mortalities. Metaphylaxis is a common management tool to mitigate BRD, however its use has led to increased antimicrobial resistance. Novel methods to mitigate BRD are needed, including microbiota-based strategies. However, information on the respiratory bacteria of beef calves prior to weaning was limited. In this study, it was shown that the microbiota of cows influenced the initial composition of both respiratory and fecal microbiotas in calves. While colonization of the respiratory tract of calves by BRD-associated genera occurred early in life, their relative abundances increased at weaning, and were negatively correlated with respiratory and gut bacteria. Thus, microbiotas of both the respiratory and gastrointestinal tracts have important roles in antagonism of respiratory pathogens and are potential targets for enhancing calf respiratory health. Modulation may be most beneficial, if done prior to weaning, before opportunistic pathogens establish colonization.