Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Ministério da Educação, Brasília, Brazil.
Appl Environ Microbiol. 2018 Apr 16;84(9). doi: 10.1128/AEM.02675-17. Print 2018 May 1.
Microbial communities play critical roles in the gastrointestinal tracts (GIT) of preruminant calves by influencing performance and health. However, little is known about the establishment of microbial communities in the calf GIT or their dynamics during development. In this study, next-generation sequencing was used to assess changes in the bacterial communities of the rumen, jejunum, cecum, and colon in 26 crossbred calves at four developmental stages (7, 28, 49, and 63 days old). Alpha diversity differed among GIT regions with the lowest diversity and evenness in the jejunum, whereas no changes in alpha diversity were observed across developmental stage. Beta diversity analysis showed both region and age effects, with low numbers of operational taxonomic units (OTUs) shared between regions within a given age group or between ages in a given region. Taxonomic analysis revealed that several taxa coexisted in the rumen, jejunum, cecum, and colon but that their abundances differed considerably by GIT region and age. As calves aged, we observed lower abundances of taxa such as , , and with higher abundances of and in the rumen. The jejunum also displayed taxonomic changes with increases in and taxa in older calves. In the lower gut, taxa such as , , and decreased and S24-7, , and increased as calves aged. These data support a model whereby early and successive colonization by bacteria occurs across the GIT of calves and provides insights into the temporal dynamics of the GIT microbiota of dairy calves during preweaning development. The gastrointestinal tracts (GIT) of ruminants, such as dairy cows, house complex microbial communities that contribute to their overall health and support their ability to produce milk. For example, the rumen microbiota converts feed into usable nutrients, while the jejunal microbiota provides access to protein. Thus, establishing a properly functioning GIT microbiota in dairy calves is critical to their productivity as adult cows. However, little is known about the establishment, maintenance, and dynamics of the calf GIT microbiota in early life. In this study, we evaluated the bacterial communities in the rumen, jejunum, cecum, and colon in dairy calves across preweaning development and show that they are highly variable early on in life before transitioning to a stable community. Understanding the dairy calf GIT microbiota has implications for ensuring proper health during early life and will aid in efforts to develop strategies for improving downstream production.
微生物群落通过影响性能和健康，在反刍前犊牛的胃肠道 (GIT) 中发挥关键作用。然而，对于犊牛 GIT 中微生物群落的建立或其在发育过程中的动态变化知之甚少。在这项研究中，使用下一代测序技术评估了 26 头杂交犊牛在四个发育阶段（7、28、49 和 63 天大）的瘤胃、空肠、盲肠和结肠的细菌群落变化。α多样性在胃肠道区域之间存在差异，空肠的多样性和均匀度最低，而发育阶段没有观察到 α 多样性的变化。β多样性分析显示了区域和年龄的影响，在给定年龄组内的区域之间或在给定区域内的年龄之间，操作分类单元 (OTU) 的数量很少。分类分析表明，在瘤胃、空肠、盲肠和结肠中存在多个共同存在的分类群，但它们的丰度因 GIT 区域和年龄而异。随着犊牛年龄的增长，我们观察到瘤胃中 、 和 的丰度降低，而 和 的丰度增加。空肠也随着年龄的增长而发生分类变化，老犊牛中 和 类群的丰度增加。在下部肠道中，随着犊牛年龄的增长， 、 和 等分类群减少，而 S24-7、 和 等分类群增加。这些数据支持了一个模型，即细菌通过早期和连续的定植发生在犊牛的 GIT 中，并提供了在反刍前发育过程中奶牛犊牛 GIT 微生物组的时间动态的见解。反刍动物（如奶牛）的胃肠道 (GIT) 中存在复杂的微生物群落，这些微生物群落有助于它们的整体健康，并支持它们产奶的能力。例如，瘤胃微生物群将饲料转化为可用的营养物质，而空肠微生物群则提供蛋白质。因此，在奶牛犊牛中建立一个正常运作的 GIT 微生物群对于它们作为成年奶牛的生产力至关重要。然而，对于犊牛 GIT 微生物群在生命早期的建立、维持和动态变化知之甚少。在这项研究中，我们评估了奶牛犊牛在整个反刍前发育过程中的瘤胃、空肠、盲肠和结肠中的细菌群落，并表明它们在生命早期非常多变，然后过渡到稳定的群落。了解奶牛犊牛 GIT 微生物群对确保早期生活中的健康具有重要意义，并将有助于开发改善下游生产的策略。
