The aim of this study was to describe the fecal bacteria and archaea composition of Holstein-Friesian and Simmental heifers and lactating cows, using 16S rRNA gene sequencing. Bacteria and archaea communities were characterized and compared between heifers and cows of the same breed. Two breeds from different farms were considered, just to speculate about the conservation of the microbiome differences between cows and heifers that undergo different management conditions. The two breeds were from two different herds. Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria were the most abundant phyla in all experimental groups. Alpha- and beta-diversity metrics showed significant differences between heifers and cows within the same breed, supported by principal coordinate analysis. The analysis of Holstein-Friesian fecal microbiome composition revealed 3 different bacteria families, 2 genera, and 2 species that differed between heifers and cows; on the other hand, Simmental heifers and cows differed only for one bacteria family, one archaeal genus, and one bacteria species. Results of the present study suggest that fecal communities of heifers and cows are different, and that fecal microbiome is maintained across experimental groups.

这项研究的目的是使用16S rRNA基因测序来描述荷斯坦-弗里斯兰和西门塔尔牛以及泌乳母牛的粪便细菌和古细菌成分。鉴定了细菌和古细菌群落，并比较了同一品种的小母牛和母牛。考虑了来自不同农场的两个品种，只是为了推测受到不同管理条件的母牛和小母牛之间微生物组差异的保留。这两个品种来自两个不同的牧群。硬毛菌，拟杆菌，放线菌和变形杆菌是所有实验组中最丰富的门。在主坐标分析的支持下，α和β多样性指标显示同一品种内小母牛和母牛之间存在显着差异。通过对荷斯坦-弗里斯兰粪便微生物组组成的分析，发现了3个不同的细菌科，2个属和2个在小母牛和母牛之间有所不同的物种。另一方面，西门塔尔小母牛和奶牛的区别仅在于一个细菌家族，一个古细菌属和一个细菌物种。本研究的结果表明，小母牛和母牛的粪便群落是不同的，并且实验组中粪便微生物组得以维持。