Fetal (GD16.5–18.5) and neonatal (PND1) relative and differential cell counts from peripheral blood smears*.

*Incidence of nucleated RBCs and erythroblastic red cells to the greater RBC population was obtained from peripheral blood smears: ∼500 RBCs were counted for each animal. A differential count was also performed to assess white cells, but yielded too few white cells to produce statistically significant differences in myeloid and lymphoid cell populations. Percent of nucleated erythroid cells (red cells with nuclei in late stages of development, plus erythroblasts), compared with all leukocytes (large, medium, and small lymphocytes, monocytes, eosinophils, basophils, neutrophils, and myeloid precursors), was determined. No plasma cells and few Howell-Jolly bodies were seen. Stain used was Wright-Giemsa, prefixed with methanol.