The characterization of vaginal microbiota will help to understand some of the reproductive problems and mechanisms to improve cattle reproduction. The objective of this study was to characterize the vaginal microbiota of cyclical Holstein cows with different parturition orders using 16S rDNA sequencing. Animals were submitted to an estrus synchronization protocol with the use of intravaginal progesterone (P4) implants and were treated or not with ceftiofur hydrochloride. DNA samples were extracted from vaginal swabs on day 0 and 10 of the synchronization, and sequenced with the Illumina MiSeq platform with an average coverage rate of 10.000 reads per samples using a Single-End library for fragments of 300 bp. The main bacterial phyla found in the vaginal tract of Holstein cows, were Firmicutes (37.61%), Tenericutes (29.45%), Proteobacteria (17.47%) and Bacteriodetes (13.73%), followed by Actinobacteria (0.82%) and Spirochaetae (0.45%). The use of intravaginal P4 devices has increased the relative abundance of the genera Family XIII AD3011 and Family XIII unclassified (p < .049). We have also observed an effect of the number of calving on the vaginal microbiota composition, showing that multiparous cows have a greater bacterial diversity than primiparous animals (p < .05). The use of ceftiofur hydrochloride was effective to reduce the vaginal bacteria proliferation. This study describes for the first time the vaginal microbiota of cows synchronized with intravaginal progesterone devices, different from the traditional methods such as microbiological culture and biochemical tests. We have identified a large number of microorganisms commonly found in the gastrointestinal tract of cows, colonizing the vaginal microbiota.

中文翻译：

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荷斯坦奶牛阴道微生物群研究使用阴道内孕酮装置进行了发情同步实验。

阴道微生物群的特征将有助于了解一些生殖问题和改善牛繁殖的机制。这项研究的目的是使用16S rDNA测序来表征具有不同分娩顺序的周期性荷斯坦奶牛的阴道菌群。使用阴道内孕酮（P4）植入物使动物接受发情同步实验，并用或未用头孢噻呋盐酸盐治疗过。在同步的第0天和第10天从阴道拭子中提取DNA样品，并使用Illumina MiSeq平台进行测序，使用300 bp的单端文库，每个样品的平均覆盖率为10.000个读数。在荷斯坦奶牛的阴道中发现的主要细菌菌群是Firmicutes（37.61％），Tenericutes（29.45％），Proteobacteria（17。47％）和拟杆菌（13.73％），其次是放线菌（0.82％）和螺旋藻（0.45％）。阴道内P4装置的使用增加了XIII系列AD3011和XIII系列未分类的相对丰度（p <.049）。我们还观察到产犊次数对阴道微生物群组成的影响，表明多头母牛比初头动物具有更大的细菌多样性（p <.05）。盐酸头孢噻呋的使用可有效减少阴道细菌的增殖。这项研究首次描述了与阴道内孕激素装置同步的奶牛阴道菌群，这与传统方法（例如微生物培养和生化测试）不同。