Hematological development of the infant squirrel monkey (Saimiri sciureus).

Hematologic developmental norms from infant squirrel monkeys indicate a relative maturation of the hematopoietic system by 16 weeks. The elevated hemoglobin, hematocrit, red blood cell count, MCV and MCH at birth are followed by a decreasing hemoglobin (decreasing red blood cell count and MCV) until 4 weeks of age. A reticulocytosis then occurs until the hemoglobin level approximates adult concentrations by 16 weeks of age with gradual changes in this as well as hematocrit, red blood cell count, MCV and MCH thereafter. Total leukocytes and segmented neutrophils are elevated at birth and decrease rapidly in the first 2 weeks, reaching stabile values by 16 weeks. An opposite trend is seen with the lymphocyte population. Plasma protein and albumin concentrations show a nadir at 2 weeks of age with the albumin levels stabilizing by 10 weeks and the total protein concentration continuing to increase throughout the 1st year.