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As part of a series of studies to characterize innate and speci¢c immune responses of indigenous chicken lines, birds from Bolivia and India were screened serologically for MHC class IV (BG) polymorphism by direct haemagglutination using haplotype-speci¢c antisera (B2, B4, B12, B13, B14, B15, B19, B21). The sample consisted of 95 Bolivian indigenous chickens and 119 hens from the four most common North Indian`back-yard' chicken lines: Yellow Aseel (AP), Kadaknath (KN), frizzled typed (Ff^) and naked neck (NN). Of all chickens tested, the majority were haplotyped as B2, B15, B19 and B21. Of the Bolivian chickens, 89.5% could be haplotyped: 54.9% were homozygous (including 43.3% B15), and 34.6% were heterozygous (including 15.7% B15). B2-like haplotypes were not found among the Bolivian hens, and only 3.2% of these birds showed homozygous B21-like proteins. Of the Indian hens, MHC (BG)-like proteins could be detected in 60.0% of the AP birds, 6.7% of the KN birds; 40.0% of the Ff^birds; and 10.3% of the NN birds. In these lines, a total of 40.1% (AP), 6.7% (KN), 30.1% (Ff^) and 10.3% (NN) were homozygous for the B-haplotype. Only in the AP line (19.9%), and the Ff^line (9.9%) were heterozygous B-haplotypes types found. The B2 haplotype was found in all Indian chicken lines. Most Indian birds have completely unknown haplotypes, indicating a potentially interesting genetic pool. Subgrouping the Bolivian and Indian indigenous hens into monomorphic BG populations revealed individual di¡erences based on the B-types.

2005.Haemolytic complement activity and humoral immune responses to sheep red blood cells in indigenous chickens and in eight German Dahlem Red chicken lines with di¡erent combinations of major genes (dwarf, naked neck and frizzled) of tropical interest. Tropical Animal Health and Production, 37(3), 173^186 ABSTRACT A total of 376 chickens from di¡erent ecotypes were immunized with the non-pathogenic multideterminant antigen sheep red blood cells (SRBC). The ecotypes included indigenous chickens from various locations in Tanzania (n = 102), India (n = 86) and Bolivia (n = 89). In addition, eight German Dahlem Red (GDR) chicken lines with di¡erent major genes (dwarf, naked neck and frizzled) of tropical interest were also immunized with SRBC. Immune competence of the breeds was assessed by measuring complement haemolytic activity, both from the classical calcium-dependent complement pathway (CPW) and alternative calcium-independent complement pathway (APW), alongside IgTotal, IgG and IgM antibody responses to SRBC at 7 days post immunization. Large variations in complement activity and antibody responses to SRBC were observed within and between the indigenous breeds. Many indigenous chickens, especially from Bolivia, showed decreased complement activity (APW) following immunization with SRBC. Breeds from India showed the highest CPW activity and humoral (especially IgM) responses to SRBC, suggesting high immune competence. In contrast, Bolivian chickens were characterized by low CPW activity, low APW activity and low antibody levels to SRBC suggesting an overall low immune competence. In the GDR chickens, characterized by high CPW activity and high IgG antibody responses to SRBC, the major genes for naked neck, frizzling and dwar¢sm had no signi¢cant e¡ect on the antibody responses and complement activity to SRBC.

2005. Serum haemolytic complement levels in German Dahlem Red chickens are a¡ected by three major genes (naked neck, dwarf, frizzled) of tropical interest. Tropical Animal Health and Production, 37(1), 1^9 ABSTRACT German Dahlem Red chickens with three di¡erent major genes of tropical interest: Nana^(naked neck), Ff^(frizzled) and dw^(dwarf), respectively, were tested for serum haemolytic complement, which is essential in innate host defence against infectious agents. Eight di¡erent combinations of genes for body size and feather coverage were evaluated. Signi¢cant di¡erences both for both the calcium-dependent (classical, CPW) and the calcium-independent (alternative, APW) complement titres were found between the phenotypes. Phenotype nana¡Dw^showed the highest complement status. The frizzled (Ff^) gene had a negative in£uence on APW titres, whereas the dwarf (dw^) gene had a negative in£uence on CPW titres. The naked neck (Nana^) gene had various in£uences on the haemolytic complement status. All tested hens had MHC (B) 21 haplotypes, whereas the gene for dwar¢sm appeared to be linked with the B19 haplotype. It was concluded that introducing major genes (Nana^, dw^, Ff^) to conquer environmental stress in hot climates can have a negative impact on certain aspects of the innate immunity of poultry.

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