Vaginal and uterine microbiomes during puerperium in dairy cows

Knowledge of how vaginal and uterine microbiomes are composed is essential to prevent uterine diseases and to understand their pathogenesis. For this purpose, 50 dairy cows were involved in a prospective trial. Cows were clinically examined and vaginal and uterine swabs were taken (day 2, 4, 6 and 14 p.p.), followed up by clinical examination on day 21 ± 1 and 41 ± 1. All samples (n = 364) were analyzed with cultural bacteriological methods and bacteria were identified by MALDI-TOF MS. In animals with a pathological puerperium, bacterial diversity was reduced and the genera Fusobacteria spp., Bacteroides spp. and Helcococcus spp. occurred significantly more frequently. By contrast, other well-known uterine pathogens such as Escherichia spp. and Trueperella pyogenes did not show significant differences between healthy and diseased cattle. Bacterial occurrences in the vagina and the uterus were sometimes correlated. Cows that suffered from puerperal disorders showed a significantly lower incidence of coagulase- negative staphylococci even before symptoms occurred. This may point towards a protective role of the vaginal microbiome. In addition, we discuss several shortcomings in calving hygiene that might have contributed to the high percentage of puerperal disorders on the study farm (58.7%).