Erythrocyte maturation in neonatal dwarf and landrace kids

The morphology of the erythrocyte cell series was investigated in external jugular vein blood samples from Dwarf and Danish Landrace goats aged from one day to 12 months. Three erythrocytic cell types were observed in neonates after supravital staining with new methylene blue. The first type were macrocytes which were stained uniformly dark to muddy blue. They formed the majority of the erythrocytic cells at birth and were categorized as diffusely basophilic chromatophilic erythrocytes. The second type were punctate and aggregated reticulocytes, and the third type were mature erythrocytes. The size ranges of the three erythrocytic cells were 4.2-5.6, 4.9-6.3 and 2.8-3.5 microns diameter respectively in the Dwarf kids and 5.6-9.7, 4.2-9.0 and 3.8-4.2 microns respectively in the Landrace kids during the first week of life. Romanowsky-stained blood smears from neonatal kids were characterized by anisocytosis and poikilocytosis in which polychromatophilic macrocytes were numerous, but reticulocytes were not clearly identifiable. The ranges of erythrocyte diameters in Romanowsky-stained neonatal blood films were 4.4-5.8 (5.2 +/- 0.39) and 4.1-6.7 (5.1 +/- 0.67) microns in Dwarf and Landrace kids respectively, decreasing to 3.0 +/- 0.15 and 3.3 +/- 0.13 microns in the two broods respectively by 12 months of age. The numbers of diffusely basophilic polychromatophilic erythrocytes and punctate/aggregated reticulocytes diminished with age and they were not observed in 1-2-month-old kids.