title: Health and performance of young dairy calves vaccinated with a modified-live Mannheimia haemolytica and Pasteurella multocida vaccine.
abstract: OBJECTIVE
  To evaluate the health and performance of young dairy calves vaccinated with a commercial Mannheimia haemolytica and Pasteurella multocida vaccine.
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  358 Holstein dairy calves between 14 and 20 days of age on 8 farms.
  
  
  METHODS
  Calves were randomly assigned to a control or vaccinated group. The vaccine used was a commercial modified-live M. haemolytica and P. multocida vaccine that was administered on days 0 and 14. Calf weight was measured on day 0 and monthly for 3 months. Farmers were asked to record any treatment given to the calves and the reason for treatment during the 4 months of the study. Blood was collected from all calves on days 0 and 28, and titers of antibodies to M. haemolytica were determined by means of direct bacterial agglutination.
  
  
  RESULTS
  Mean daily gain was not significantly different between vaccinated and control calves. Vaccinated calves had a significantly greater increase in antibody titers (5.3-fold increase), compared with control calves (3.6-fold increase). There was no significant difference between vaccinated and control calves for any of the treatment outcomes (number and duration of treatments and age at first and last treatments).
  
  
  CONCLUSIONS
  Results suggest that the M. haemolytica and P. multocida vaccine, given twice 2 weeks apart, was effective in increasing titers of antibodies against M. haemolytica in young dairy calves but did not improve calf performance or health.
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
authors.forename: P
authors.initials: P
authors.lastname: Aubry
authors.forename: L D
authors.initials: LD
authors.lastname: Warnick
authors.forename: C L
authors.initials: CL
authors.lastname: Guard
authors.forename: B W
authors.initials: BW
authors.lastname: Hill
authors.forename: M F
authors.initials: MF
authors.lastname: Witt
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000907:Antibodies, Bacterial / Q000097:blood; D001428:Bacterial Vaccines / Q000008:administration & dosage; D002417:Cattle; D005260:Female; D016978:Mannheimia haemolytica / Q000276:immunology*; D016979:Pasteurella multocida / Q000276:immunology*; D012766:Pasteurellosis, Pneumonic / Q000276:immunology / Q000517:prevention & control*; D016896:Treatment Outcome; D014611:Vaccination / Q000662:veterinary; D015430:Weight Gain
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines