The Fecal Microbiota of Healthy and Diarrheic Calves Before, During and at Recovery From Diarrhea

Thumbnail Image


Journal Title

Journal ISSN

Volume Title


University of Guelph


The changes associated with the gastrointestinal microbiota before, during and after neonatal calf diarrhea still needs to be fully understood and described. The first chapter of this thesis reviews our current understanding of the composition of a “healthy” fecal microbiome, microbial changes associated with dysbiosis and gastrointestinal disease, etiologic agents associated with diarrhea, and current treatments for calf diarrhea. Throughout the literature review, the author explains the current knowledge gaps regarding the changes in the gastrointestinal microbial communities of calves that experience diarrhea during the preweaning period and provides opinions about future studies that can aid in filling those gaps.
The second chapter reports the findings of a study investigating the changes in the fecal microbiota of neonate calves before, during, and at recovery of diarrhea. This study showed that the bacterial communities of healthy calves and calves that experience diarrhea are not different before or after diarrhea, but the microbiota differed between groups at diarrhea onset. These results suggested that reported changes in bacterial communities during diarrhea appear to be a consequence of diarrhea and gastrointestinal inflammation rather than the predisposing factor for diarrhea development.



Dairy cattle, Dysbiosis, Enteropathogens, Gastrointestinal microbiome, Neonate