Interrelationships of the Blood Cells of Cattle in Health and Following an Induced Infection with Brucella Abortus

The age of the animals was definitely but negatively correlated with the total number of both red and white blood cells per unit volume of blood. Very slight, although statistically significant associations were found between age and the proportions of each of the types of the circulating leucocytes, except eosinophiles, prior to the exposure. The infection with Brucella abortus resulted principally in a loss of the significant correlation of age and number of white blood cells, with slight changes in the associations between age and the different types of leucocytes. The advance in stage of pregnancy was only slightly and inversely correlated with any of the parts of the cellular picture. Following the exposure, the associations were more pronounced, with greater positive correlations between stage of pregnancy and both neutrophiles and monocytes. The most significant positive correlations were found between the total number of red and white blood cells per unit volume of blood, and inversely between the proportions of the following types of white blood cells, in descending order: neutrophiles with lymphocytes, eosinophiles and monocytes; monocytes with lymphocytes and eosinophiles; lymphocytes with eosinophiles. Only a few of these relationships between the proportions of the types of leucocytes were changed to any extent during the induced infection. These data presented on the association of different parts of the cellular picture of individuals add further support to the proposal that each animal in health has a blood picture peculiar to itself.