Metabolic and cellular profile testing in calves uncer feedlot conditions: blood cellular components--reference values and changes over time in feedlot.

The cellular components of the blood of 114 calves were measured under feedlot conditions. The results suggest that certain cellular components of the blood of a group of crossbred feedlot-type calves which are homogeneous only with regard to weight are reasonably uniform. More specifically, all red blood cell components have coefficients of variation of less than 10%. The white blood cell counts underwent drastic changes over the first 2 sampling dates, ie, before and after transport and processing of the calves. Later, in the feeding period, the cell counts readjusted to more stable levels. The results were compared with such values obtained from dairy cattle. The total erythrocyte count, total leukocyte count, and red blood cell components were found to be slightly higher in these feedlot calves than in dairy cattle. The difference might partly be due to age. The mean values reported can be used as a base for comparison with values obtained from other such studies or from studies of disease processes in cattle under feedlot conditions (or both).