Erythrocytic Blood Picture of the Korean Native Cattle from Birth to Maturity

한우의 성장에 따르는 적혈구상의 변동

Little work has been done on the changes in the blood picture occurring at different ages in cattle. In our country Kim (1963) and Jeong (1965) recorded the blood picture of mature Korean native cattle and, recently, Mun et al. (1974) has recorded the blood picture of Holstein cows. And a comprehensive survey of the blood picture of Korean native cattle has not been made. The object of the present investigation was to make good this deficiency, and to suggest standards for the blood picture of Korean native cattle at frequent intervals from birth to maturity. The cattle were kept under average farming conditions in this country. Observations were made at the following ages: at birth; 1, 2 and 4 days; 1, 2 and 4 weeks; 2,4,6 and 9 months; 1, 2 and 3 years of age. Blood samples were drawn from the jugular vein. Erythrocyte enumerations, concentration of hemoglobin in blood and hematocrit values were made in usual manner. Erythrocyte counts increased from $8{\times}10^6/mm^3$ during the first week to a level of $10{\times}10^6/mm^3$ at 2 months of age, showing steady state untill 6 months of age; it then fell to adult level ($8{\times}10^6/mm^3$) at 9 months of age. Concentration of hemoglobin in blood and hematocrit values were closely related to the changes of erythrocyte counts. The values increased from 10 g/100 ml and 31~35 ml/100 ml during the early life to 11 g/100 ml and 38 ml/100 ml at 2 months of age, showing steady state untill 6 months of age; these then fell to adult level (10 g/100 ml and 31~34 ml/100 ml) at 9 months of age for concentration of hemoglobin in blood and hematocrit values, respectively. Mean corpuscular volume and mean corpuscular hemoglobin showed a common pattern. The values were $42{\sim}43{\mu}m^3$ and 12.4 pg during the early life and fell a little to 6~9 months of age; these then increased to reach adult levels of $43{\mu}m^3$ and 12.6 pg for mean corpuscular volume and mean corpuscular hemoglobin, respectively. Mean corpuscular hemoglobin concentration was little affected with age.