Reticulocyte numbers in Japanese quail chicks.

Erythrocyte parameters in Coturnix coturnix japonica were evaluated daily during the first 2 weeks after hatching. Nadirs in total circulating erythrocyte numbers, hematocrit percentages, and hemoglobin concentrations were found during the first 5 days posthatch. Reticulocytosis from 4 to 9 days posthatch ameliorated these nadirs until 12 days posthatch, when secondary nadirs appeared. Erythropoiesis was indicated by reticulocytosis when hemoglobin levels decreased. Reticulocyte maturation was indicated from 3 to 6 days after the onset of erythropoiesis by the predominance of mature erythrocytes in circulation.