title: Quantitative measures of disease in broiler breeder chicks of different major histocompatibility complex genotypes after challenge with infectious bursal disease virus.
abstract: Criteria for evaluating genetic differences in resistance and susceptibility to infectious bursal disease (IBD) within a commercial broiler breeder line of chickens were compared. Line A broiler breeder chickens were challenged with graded doses of Animal and Plant Health Inspection Service (APHIS) strain IBD virus (IBDV) and evaluated at 2 time points, 3 days postinoculation (PI) and 10 days PI. Measures obtained at both time points included bursa to body weight, bursa histology, bursa lymphocyte count, and percentage of T cells in the bursa. Furthermore, viral load in the bursa was determined 3 days PI and anti-IBDV antibody titers, 10 days PI. A dose of 50 50% embryo infective dose caused IBD in about half the line A birds at the 10-day time point, and this dose was chosen for further studies. The data were analyzed for correlation among the various measures. Comparison of the 3-day- and 10-day-PI bursa lymphocyte counts indicated that birds challenged with low doses of virus suffered lymphocyte depletion at the 3-day time point, but many or all (depending on the dose) recovered by the 10-day time point. With a viral dose that caused bursal atrophy in about half the birds by 10 days PI, families segregating for 2 major histocompatibility complex (MHC) haplotypes were compared in terms of resistance to IBD. Results indicated that there was no difference among the 3 MHC genotypes in incidence of IBD by any of the disease measures.
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849-5519, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Hudson
authors.forename: E J
authors.initials: EJ
authors.lastname: Hoerr
authors.forename: S H
authors.initials: SH
authors.lastname: Parker
authors.forename: S J
authors.initials: SJ
authors.lastname: Ewald
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis; D018175:Birnaviridae Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D001835:Body Weight; D002060:Bursa of Fabricius / Q000276:immunology / Q000473:pathology / Q000821:virology; D002645:Chickens / Q000235:genetics / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005838:Genotype; D006239:Haplotypes; D007113:Immunity, Innate; D007243:Infectious bursal disease virus / Q000276:immunology / Q000472:pathogenicity*; D018655:Lymphocyte Count / Q000662:veterinary; D008285:Major Histocompatibility Complex / Q000235:genetics*; D008297:Male; D011201:Poultry Diseases / Q000235:genetics / Q000276:immunology* / Q000821:virology; D013601:T-Lymphocytes; D019562:Viral Load / Q000662:veterinary
chemical_list: D000914:Antibodies, Viral