Characterization of the Fecal Bacterial Microbiota of Healthy and Diarrheic Dairy Calves

Gomez, D.E.; Arroyo, L.G.; Costa, M.C.; Viel, L.; Weese, J.S.

Fifteen diarrheic calves between the ages of 1 and 30 days, and 15 age-matched healthy control calves were enrolled from each farm. Health status of the calves was assessed with a standardized calf health-scoring chart. 13 This system assisted the assessment of health by evaluating body temperature score (0, 1 = normal; 2, 3 = fever), fecal score (0, 1 = normal; 2, 3 = diarrhea), nasal score (0, 1 = normal; 2, 3 = nasal discharge), eye score (0, 1 = normal; 2, 3 = eye discharge, crusty eyes), and ear score (0, 1 = normal; 2, 3 = head tilt, 1 ear or both ears dropped). A diarrheic calf was defined as a calf with fecal and body temperature scores ≥2 and score ≤1 in the other evaluated systems. Once a diarrheic calf was identified, an age-matched (AE2 days) control calf with health score ≤1 in all of the evaluated systems was enrolled. Calves were not included in the study if they had a previous episode of diarrhea, other diseases (eg, umbilical abscess, pneumonia), or if they had ever been treated with antimicrobial drugs. Healthy calves that developed diarrhea within the 10 days after sampling also were excluded. Fecal samples were obtained per rectum from cases and controls, labeled and immediately stored at À20°C.