SRP493920 PRJNA1083747 16S rRNA gene amplicon sequencing of feces of retained placenta in dairy cows at one week before the due date Traditional sampling methods for determining a retained placenta in dairy cows can induce a stress response and premature delivery. In this study, we screened noninvasive potential early warning biomarkers for retained placenta in dairy cows. Via 16S rRNA gene amplicon sequencing analysis, we discovered three biomarkers, Oscillospiraceae UCG005 and Escherichia Shigella from the fecal microbiome. We believe that our study makes a significant contribution to the literature because these potential early warning biomarkers can help predict retained placenta occurrence in the early perinatal period and reduce placental retention in dairy cows via early intervention. Our study provides new ideas for the development of noninvasive early warning technologies for retained placenta in dairy cows.