PLASMA CORTICOID LEVELS IN HEALTHY AND DIARRHEIC CALVES FROM BIRTH TO 20 DAYS OF AGE

Concentrations of adrenal corticosteroids were determined by a competitive protein-binding technique in jugular blood plasma obtained from 21 calves within 5 min of birth, and every morning for the following 20 days. In calves which remained healthy, concentrations dropped rapidly during the first 5 days and more gradually over the following 10 days to reach a steady level of 2.2 ng/ml. Levels in calves which later developed diarrhea were higher during the first 4 days of life than in calves which remained healthy. The levels in diarrheic calves also decreased with age, except during periods of scouring.