title: Evaluation of a commercially available immunoassay for assessing adequacy of passive transfer in calves.
abstract: OBJECTIVE
  To evaluate diagnostic utility of a commercially available immunoassay for assessing adequacy of passive transfer of immunity in neonatal calves.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  123 calves.
  
  
  METHODS
  Blood and serum samples were obtained from the calves prior to 2 weeks of age. The immunoassay was performed, along with refractometry and an 18% sodium sulfite turbidity test. Serum IgG concentration was determined with a radial immunodiffusion assay. Sensitivity and specificity of the immunoassay, refractometry, and the sodium sulfite test were calculated by comparing results with results of the radial immunodiffusion assay.
  
  
  RESULTS
  Sensitivity and specificity of the blood IgG immunoassay were 0.93 and 0.88, respectively, compared with 1.00 and 0.53 for the sodium sulfite test. For refractometry, sensitivity and specificity were 0.71 and 0.83, respectively, when a serum total solids concentration of 5.2 g/dl was used as the cutoff between positive and negative test results.
  
  
  CONCLUSIONS
  Results suggest that the immunoassay performs well in detecting calves with inadequate passive transfer of immunity.
authors.affiliation: Department of Veterinary Medicine and Surgery College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
authors.forename: Maisie E
authors.initials: ME
authors.lastname: Dawes
authors.forename: Jeff W
authors.initials: JW
authors.lastname: Tyler
authors.forename: Douglas
authors.initials: D
authors.lastname: Hostetler
authors.forename: Jeff
authors.initials: J
authors.lastname: Lakritz
authors.forename: Ronald
authors.initials: R
authors.lastname: Tessman
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000097:blood / Q000276:immunology*; D002417:Cattle / Q000097:blood / Q000276:immunology*; D007112:Immunity, Maternally-Acquired; D007118:Immunoassay / Q000592:standards / Q000662:veterinary*; D005779:Immunodiffusion / Q000662:veterinary; D007074:Immunoglobulin G / Q000097:blood*; D009391:Nephelometry and Turbidimetry / Q000662:veterinary; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic / Q000592:standards / Q000662:veterinary; D012031:Refractometry / Q000662:veterinary; D012680:Sensitivity and Specificity; D013447:Sulfites
chemical_list: D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic; D013447:Sulfites; C025026:sodium sulfite