title: Association of bovine respiratory disease or vaccination with serologic response in dairy heifer calves up to three months of age.
abstract: OBJECTIVE
  To investigate the association of bovine respiratory disease (BRD) or vaccination with serologic response in calves.
  
  
  METHODS
  94 Holstein calves.
  
  
  METHODS
  To assess the association between BRD and antibody titers, 38 calves < 3 months old that were treated for BRD were matched with 38 untreated calves. To investigate the effect of vaccination on antibody titers, 24 calves were randomly assigned to be vaccinated against bovine respiratory syncytial virus (BRSV), bovine viral diarrhea virus types 1 and 2, bovine herpesvirus type 1 (BHV1), and parainfluenza virus type 3 at 2 weeks of age (n = 6), 5 weeks of age (6), and both 2 and 5 weeks of age (6) or were assigned to be unvaccinated controls (6). Blood samples were obtained at I, 2, 5, and 12 weeks for determination of serum neutralization antibody titers against the vaccine viruses, bovine coronavirus, and Mannheimia haemolytica. Antibody rates of decay were calculated.
  
  
  RESULTS
  Calves with initial antibody titers against BRSV < 1:64 that were treated for BRD had a slower rate of anti-BRSV antibody decay than did similar calves that were not treated for BRD. Calves with high initial antibody titers against BRSV and BHV1 had lower odds of BRD than did calves with low initial antibody titers against those 2 pathogens. Vaccination at 2 or 5 weeks of age had no effect on the rate of antibody decay.
  
  
  CONCLUSIONS
  Clinical BRD and the serologic response of dairy calves were associated with initial antibody titers against BRSV and BHV1. Serologic or clinical responses to viral exposure may differ in calves with low passive immunity.
authors.affiliation: Department of Population Medicine, Ontario Veterinary College, University of Guelph, Guelph, ON NIG 2WI, Canada.
authors.forename: M Claire
authors.initials: MC
authors.lastname: Windeyer
authors.forename: Ken E
authors.initials: KE
authors.lastname: Leslie
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Godden
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Hodgins
authors.forename: Kerry D
authors.initials: KD
authors.lastname: Lissemore
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: LeBlanc
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000097:blood; D016022:Case-Control Studies; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000517:prevention & control*; D003612:Dairying; D030241:Diarrhea Virus 1, Bovine Viral / Q000276:immunology; D005260:Female; D007242:Herpesvirus 1, Bovine / Q000276:immunology; D008297:Male; D016978:Mannheimia haemolytica / Q000276:immunology; D029101:Parainfluenza Virus 3, Bovine / Q000276:immunology; D018357:Respiratory Syncytial Virus Infections / Q000097:blood / Q000517:prevention & control / Q000662:veterinary*; D018112:Respiratory Syncytial Virus, Bovine / Q000276:immunology; D012189:Retrospective Studies; D014611:Vaccination / Q000662:veterinary; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D014765:Viral Vaccines