Description:The Track Dairy Cattle (trackDC) study is a longitudinal study in northern China that aims to track newborn calves to assess the development of gut microbiota during early life that contributes to cattle health and production. In this study, 36 newborn calves were randomly assigned to three groups and followed for two months after birth. The groups included a control group (CON), a rumen microbiota transplantation group (RMT), and a rumen fluid transplantation group (RFT) and intensive data has been collected. Blood samples were collected at 15, 35, and 56 days after birth.