Evaluating the Effectiveness of Colostrum as a Therapy for Diarrhea in Preweaned Dairy Calves

This thesis is an investigation of the efficacy of colostrum as a therapy for diarrhea in preweaned calves by evaluating the time to resolution of diarrhea, growth during the preweaning period and changes made to the fecal microbiome of treated calves. Calves treated with 65 g/L of milk replacer mixed with 65 g/L of colostrum replacer fed at 2.5 L, 8 times over 4 days compared to calves fed 2.5 L of milk replacer at 130 g/L twice daily had a faster resolution from an abnormal fecal score and had improved growth during the preweaning period. Although no differences were found in the alpha diversity of the fecal microbiome, the relative abundance of several taxa were significantly different across and within treatment groups. Future research should focus on the optimal dose and duration of colostrum therapy to provide an effective and practical alternative therapy for diarrhea in young calves.