Microbial diversity in the rumen of calves with differents time of contact with dam

This manuscript investigates the effects of maternal rearing time on calf health and rumen microbiota development in dairy calves. The practice of separating calves from their mothers at birth is common in dairy farming, but is associated with welfare problems, including digestive dysfunction and impaired mother-calf relationships. We investigated an intermediate management practice of allowing four weeks of maternal contact and compared its effects with immediate separation and traditional delayed separation at weaning. Our analysis of rumen microbiota revealed distinct evolutionary trajectories in bacterial communities based on the duration of dam contact, highlighting a significant and long-lasting effect on the gastrointestinal microbiota. However, we found no discernible effect on health-related parameters. This research contributes to the understanding of how rearing practices influence the gastrointestinal microbiota and highlights the importance of optimising management strategies to improve calf welfare in dairy systems, making it relevant to the field of veterinary science.