Postpartum compositional changes in bovine calf nasal and dam vaginal microbiota and concurrent D2Dx immune responses following prepartum betadine lavages

Lay Summary Microbial communities play an important role in immune function and overall health. In cattle, little is known about how microbial communities change after calving or how the cow’s microbial communities may influence early microbial development in the calf. This study evaluated whether altering the cow’s vaginal microbial community before calving would affect the cow and calf microbial community and immune responses post-partum. Beef cows were assigned to receive a betadine vaginal lavage prior to calving or no treatment. Vaginal samples from cows, nasal samples from calves, and blood samples from both were collected at birth and at 15, 30, and 60 days after calving. Microbial communities were evaluated using DNA sequencing, and immune responses were measured using a blood-based immune assay. Betadine lavages prior to calving did not change the cow’s vaginal microbial community after calving. In calves, the nasal microbial community differed at birth between treatment groups, but differences were transient and subsequent changes were driven primarily by age. These results suggest that healthy beef cows maintain a stable vaginal microbial community after calving and that calf nasal microbial development is driven more by age and immune maturation than by short-term changes in the dam’s vaginal microbiota.