Postnatal changes in erythrocyte 2,3-diphosphoglycerate in sheep and cattle

The concentration of 2,3-diphosphoglycerate in erythrocytes, the percentage of reticulocytes present and the haemoglobin electrophoretic patterns were investigated in blood of newborn lambs and calves. A significant rise in the concentration of 2,3-diphosphoglycerate was observed soon after birth in both lambs and calves which corresponded to a similar rise in reticulocytes and the presence of fetal haemoglobin. The increases in reticulocytes and 2,3-diphosphoglycerate concentration were greater in newborn lambs than calves but the return of 2,3-diphosphoglycerate concentrations to adult levels took longer in calves.