Quantitative measures of disease in broiler breeder chicks of different major histocompatibility complex genotypes after challenge with infectious bursal disease virus.
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.
Hudson
J C
JC
Department of Pathobiology, College of Veterinary Medicine, Auburn University, AL 36849-5519, USA.
Hoerr
E J
EJ
Parker
S H
SH
Ewald
S J
SJ
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
D000914:Antibodies, Viral