Affordable Access

deepdyve-link
Publisher Website

Ambient ammonia does not appear to inhibit the immune response to infectious bronchitis virus vaccination and protection from homologous challenge in broiler chickens.

Authors
  • Aston, E J1
  • Jackwood, M W1
  • Gogal, R M Jr2
  • Hurley, D J3
  • Fairchild, B D4
  • Hilt, D A1
  • Cheng, S1
  • Tensa, L R1
  • Garcia, M1
  • Jordan, B J5
  • 1 Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, 953 College Station Rd., Athens, GA 30602, USA. , (Georgia)
  • 2 Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, 501 D. W. Brooks Dr., Athens, GA 30602, USA. , (Georgia)
  • 3 Food Animal Health and Management Program, Department of Population Health, College of Veterinary Medicine, University of Georgia, 501 D. W. Brooks Dr., Athens, GA 30602, USA. , (Georgia)
  • 4 Department of Poultry Science, College of Agricultural and Environmental Sciences, University of Georgia, 110 Cedar St., Athens, GA 30602, USA. , (Georgia)
  • 5 Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, 953 College Station Rd., Athens, GA 30602, USA; Department of Poultry Science, College of Agricultural and Environmental Sciences, University of Georgia, 110 Cedar St., Athens, GA 30602, USA. Electronic address: [email protected] , (Georgia)
Type
Published Article
Journal
Veterinary immunology and immunopathology
Publication Date
Aug 23, 2019
Volume
217
Pages
109932–109932
Identifiers
DOI: 10.1016/j.vetimm.2019.109932
PMID: 31472338
Source
Medline
Keywords
Language
English
License
Unknown

Abstract

Commercial broilers are commonly exposed to gaseous ammonia (NH3) originating from degradation of nitrogen-containing excreta in the litter during the grow-out period. Ammonia concentrations in the air are higher in poorly ventilated houses and appear to coincide with the elevated incidence of respiratory disease occurring during the winter months. This study examined the effect of NH3 on the immune response to infectious bronchitis virus (IBV) vaccination and protection against homologous serotype challenge in commercial broiler chickens. One-day-old chicks were administered IBV vaccine and exposed to 30-60 ppm of NH3. At 28 DOA, birds were challenged oculonasally with a pathogenic homologous IBV, and protection was measured by viral detection, clinical signs, ciliostasis, and presence of airsacculitis. IBV-specific serum IgG and lacrimal fluid IgA titers, as well as Harderian gland (HG) immune cell phenotypes, were evaluated. Ammonia exposure was associated with an increased incidence of airsacculitis among non-vaccinated, challenged birds. Vaccinated, NH3-exposed birds were completely protected from IBV challenge. Ammonia had subtle effects on cilia morphology and function but did not affect vaccine or challenge virus replication and clearance, clinical signs, ciliostasis, tracheal histopathology scores, or immune responses. In the HG of vaccinated birds, the percent of leukocytes, MHC I+/MHC IIhi expression, IgM+ expression, and CD8+ expression was increased, while mucosal IgA and serum IgG titers were nominal. Non-vaccinated, IBV-challenged birds exhibited an increased percent of leukocytes, MHC I+/MHC IIhi expression, and IgM+ expression in the HG at 5 dpc, followed by increased mucosal IgA and serum IgG titers and CD8+ expression at 10-14 dpc. In contrast, vaccinated, IBV-challenged birds had a minimal increase in MHC I+/MHC IIhi expression, and serum IgG antibody titers in vaccinated birds increased rapidly. The results indicate that commercial broilers exposed to moderate levels of ambient NH3 are equally protected against IBV challenge if appropriately vaccinated, and the absence of robust immune activation in vaccinated, challenged birds suggests that the challenge virus was efficiently neutralized before establishing infection. In contrast, ambient NH3 exposure was associated with a higher incidence of airsacculitis in non-vaccinated, challenged birds, despite the apparent lack of differences in the immune response between birds in the NH3-exposed and NH3 control groups. Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.

Report this publication

Statistics

Seen <100 times