title: Reference values for selected hematologic and biochemical variables in Holstein bulls of various ages.
abstract: OBJECTIVE
  To determine reference ranges for hematologic and serum biochemical variables of bulls residing at an artificial insemination center.
  
  
  METHODS
  225 healthy Holstein bulls categorized by age into yearling, intermediate age, and adult groups.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  Reference values for selected clinicopathologic variables were generated from the data.
authors.affiliation: Select Sires Inc, Plain City, OH 43064, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Monke
authors.forename: G J
authors.initials: GJ
authors.lastname: Kociba
authors.forename: M
authors.initials: M
authors.lastname: DeJarnette
authors.forename: D E
authors.initials: DE
authors.lastname: Anderson
authors.forename: W H
authors.initials: WH
authors.lastname: Ayars
mesh_terms: D000375:Aging / Q000097:blood*; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D001772:Blood Cell Count / Q000662:veterinary; D001774:Blood Chemical Analysis / Q000662:veterinary; D001798:Blood Proteins / Q000032:analysis; D002417:Cattle / Q000097:blood*; D004909:Erythrocyte Indices / Q000662:veterinary; D008297:Male; D012016:Reference Values
chemical_list: D001798:Blood Proteins; D000469:Alkaline Phosphatase