title: Colostral immunoglobulin concentrations in Holstein and Guernsey cows.
abstract: OBJECTIVE
  To compare the concentration of IgG in colostrum between Holstein and Guernsey cows and among cows of various lactations.
  
  
  METHODS
  Cross-sectional cohort study.
  
  
  METHODS
  Colostrum samples from 77 Holstein and 24 Guernsey cows.
  
  
  METHODS
  Colostrum samples were obtained from 101 cows. Colostral IgG concentration was determined, using a radial immunodiffusion assay. Regression analysis was used to determine the effect of breed and lactation number on colostral IgG concentration. Survival analysis and t-tests were used to compare the proportion of colostrum samples that would provide 100 g of IgG for various volumes of colostral intake.
  
  
  RESULTS
  Guernsey cows produced 36.4 g of IgG/L of colostrum more than that of Holstein cows. Cows in the third or greater lactation produced 19.5 g of IgG/L of colostrum more than that of first-lactation cows. The IgG concentration of colostrum produced by second-lactation cows did not differ significantly from that produced by first-lactation cows. The colostral IgG concentration of these Holstein and Guernsey cows was higher than values that have been reported elsewhere.
  
  
  CONCLUSIONS
  Volume of colostrum needed to meet IgG intake goals is probably lower for Guernsey cows than Holstein cows. Colostrum from first-lactation cows was adequate in IgG content. The practice of discarding colostrum from first-lactation cows on the basis of inadequate IgG content was not justified in this study.
authors.affiliation: Department of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Tyler
authors.forename: B J
authors.initials: BJ
authors.lastname: Steevens
authors.forename: D E
authors.initials: DE
authors.lastname: Hostetler
authors.forename: J M
authors.initials: JM
authors.lastname: Holle
authors.forename: J L
authors.initials: JL
authors.lastname: Denbigh
mesh_terms: D000818:Animals; D001947:Breeding; D002417:Cattle / Q000276:immunology* / Q000502:physiology; D015331:Cohort Studies; D003126:Colostrum / Q000276:immunology*; D003430:Cross-Sectional Studies; D005260:Female; D007112:Immunity, Maternally-Acquired; D005779:Immunodiffusion / Q000662:veterinary; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D007774:Lactation / Q000276:immunology; D015999:Multivariate Analysis; D010298:Parity; D012044:Regression Analysis
chemical_list: D007074:Immunoglobulin G