title: Evaluation of a cow-side immunoassay kit for assessing IgG concentration in colostrum.
abstract: OBJECTIVE
  To determine sensitivity and specificity of a cow-side immunoassay kit for assessing IgG concentration in colostrum.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  76 dairy and 11 beef cows of various parities.
  
  
  METHODS
  Colostrum from first, second, and third milkings and milk samples were collected, and IgG concentration was determined by means of radial immunodiffusion. The immunoassay was performed according to the manufacturer's instructions, and sensitivity and specificity were calculated by comparing results of the immunoassay (positive vs negative) with results of immunodiffusion (< 50 g/L vs > or = 50 g/L).
  
  
  RESULTS
  135 colostrum or milk samples were collected. Mean +/- SD colostral IgG concentrations, determined by means of radial immunodiffusion for dairy and beef cows were 65.4 +/- 51.4 g/L and 114.8 +/- 42.7 g/L, respectively. Mean IgG concentrations for first-, second-, and third-milking colostrum samples and for milk samples were 92 +/- 49.0 g/L, 74.6 +/- 45.1 g/L, 47.5 +/- 32 g/L, and 6.8 +/- 3.8 g/L, respectively. Sensitivity of the immunoassay (ie, percentage of samples with IgG concentration < 50 g/L with a positive immunoassay result) was 93%, and specificity (ie, percentage of samples with IgG concentration > or = 50 g/L with a negative immunoassay result) was 76%.
  
  
  CONCLUSIONS
  Results suggested that the immunoassay kit was an acceptable cow-side test to identify colostrum samples with IgG concentrations < 50 g/L. The immunoassay kit should be useful in screening colostrum for adequate IgG concentration before feeding to calves or storage.
authors: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA.
authors: Munashe
authors: M
authors: Chigerwe
authors: Maisie E
authors: ME
authors: Dawes
authors: Jeff W
authors: JW
authors: Tyler
authors: John R
authors: JR
authors: Middleton
authors: Malantus P
authors: MP
authors: Moore
authors: Dusty M
authors: DM
authors: Nagy
mesh_terms: D000818:Animals; D002417:Cattle / Q000276:immunology* / Q000502:physiology; D003126:Colostrum / Q000276:immunology*; D005260:Female; D007118:Immunoassay / Q000379:methods / Q000592:standards / Q000662:veterinary*; D005779:Immunodiffusion / Q000379:methods / Q000662:veterinary; D007074:Immunoglobulin G / Q000032:analysis*; D007774:Lactation / Q000276:immunology; D008892:Milk / Q000276:immunology; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
chemical_list: D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic