Abstract
Objective
To determine reference ranges for hematologic and serum biochemical variables of bulls residing at an artificial insemination center.
Animals
225 healthy Holstein bulls categorized by age into yearling, intermediate age, and adult groups.
Procedure
Hematologic and serum biochemical analyses were performed on 1 blood and 1 serum sample from each bull.
Results
Significant differences associated with age were identified for 25 of 33 variables. Serum creatinine concentration for clinically normal adult bulls (2.44 ± 0.33 mg/dl) was higher than previously reported reference values for adult cattle. There was a reversal of the segmented neutrophil-to-lymphocyte ratio between yearling (0.85:1) and adult (2.6:1) bulls. This was associated with a significant and marked decrease in absolute numbers of lymphocytes per microliter between yearling (5,801 ± 1,683) and adult (1,307 ± 509) bulls.
Clinical Relevance
Reference values for selected clinicopathologic variables were generated from the data. (Am J Vet Res 1998;59:1386–1391)
