Screening potential biomarkers for early pregnancy in heifers based on combined 16S rDNA gene sequencing and serum metabolomics analysis

Early pregnancy diagnostic techniques have consistently been a significant element of livestock farming, particularly in the context of dairy farming. The aim of this study was to examine the changes in vaginal microflora abundance and serum metabolite concentrations on day 21 of gestation and to investigate the correlation between these changes and the concentrations of metabolites in the serum. The study found that five biomarkers were significantly associated with early pregnancy in heifers.