Abstract
Although considerable research has been done on the changes associated with age in the blood picture of domestic and laboratory animals, little work has been made of the changes occurring at different age in the blood picture of goats. And a comprehensive survey of the bood picture of Korean native goats has not been made. The object of the present investigation was to suggest standards for the blood picture of Korean native goats at frequent intervals from birth to maturity. The goats were kept under average farming conditions in this country. Observations were made at the following ages: at birth; 2,4 and 7 days; 2, 3, 4, 5, 6, 7, 8 and 9 weeks; 2.5, 3,6 and 12 months. Blood samples were drawn from the jugular vein. It was taken between 8 and 9 a.m. except those for the at-birth period. Erythrocyte and leukocyte enumerations and, determinations of hemoglobin in blood and hematocrit value were made in the usual manner. Reticulocytes were enumerated per 1,000 erythrocytes in blood smears stained with briIliant cresyl blue and counterstained with Wright's stain. Erythrocytes counts declined from $8.7{\times}10^8/mm^3$ at birth to a low of 7.0 at 4 days of age. These values increased to 11.5 at 5 weeks and reached a maximum of 14.0 at 3 months of age; it then fell to 11.5 at 12 months of age. Concentrations of hemoglobin in blood and hematocrit values were not related to the changes of erythrocyte counts. The values at birth were higher than at any other period during the first year of life. These fell from highs of 12.3 g/100 ml and 38.0 ml/100 ml to lows of 9.2 and 29 at 4 weeks for concentration of hemoglobin in blood and hematocrit value, respectively. There was a common pattern for the hematocrit value and hemoglobin in blood which showed three phases-a fall during the first month, a rise to the third month, and a fall to the mature level at 12 months of age. Mean corpuscular volume and mean corpuscular hemoglobin showed a common pattern. The values were $44.2{\mu}m^3$ and 14.2 pg at birth and fell, at first slowly and then rapidly, to reach adult levels of 24.1 and 7.9 at 6 weeks of age for mean corpuscular volume and mean corpuscular hemoglobin, respectively. Mean corpuscular hemoglobin concentration was little affected by age. Reticulocyte was observed from birth to 4 weeks of age. Percentage of reticulocyte decreased from 0.85% at birth to 0.06% at 4 weeks of age. Total leucocyte counts increased from $5.64{\times}10^3/mm^3$ at birth to a maximum of 13.4 at 3 months; it then fell to 11.5 at 12 months of age. In differential counts myelocyte, juvenile and band form decreased with advancing age. No myelocyte and juvenile were seen after the age of 7 and 9 weeks, respectively, and band forms were rare after the age of 3 months. Percentage of mature neutrophil showed a quick decline from 52.5% at birth to reach a minimum level (34.5%) at 3 months of age; it then rose to 38% at 12 months of age. Percentage of lymphocyte increased from 39.2% at birth to maximum of 59% at 3 month of age; it then fell to 54.9% at 12 months of age. Percentage of monocyte was not affected with advance of age. Percentage of eosinophil and basophil were increased with advance of age to reach a maximum at 2 to 3 month of age. It then fell to adult level at 12 month of age.