Association of Major Histocompatibility Complex Polymorphism With Acute Phase Response in Broiler Chicken

Area of Science:

• Animal Genetics
• Immunology
• Poultry Science

Background:

• Host immunity is influenced by stress from environmental, endogenous, or infectious factors.
• Genetic diversity in chickens is crucial for varying resistance and susceptibility to immune challenges.

Purpose of the Study:

• To investigate the association between major histocompatibility complex (MHC) polymorphism and the acute phase response (APR) in Ross 308 broiler chickens.
• To identify specific MHC alleles that correlate with immune response markers under stress conditions.

Main Methods:

• Determined allelic diversity of the LEI0258 microsatellite marker in 120 Ross broilers.
• Analyzed acute phase proteins (APPs) like serum amyloid A (SAA) and alpha-1-acid glycoprotein (AGP) as APR markers.
• Examined leukocyte counts, heterophil/lymphocyte (H/L) ratio, and antibody response to Newcastle disease vaccine (NDV).

Main Results:

• Identified six MHC alleles (195–448 bp).
• MHC alleles significantly influenced APPs in the Ross population (p < 0.05).
• Allele 448 correlated with SAA and H/L ratio; Allele 207 with AGP; Allele 195 with negative association to AGP, basopenia, and monocytosis.

Conclusions:

• MHC acts as a significant candidate gene marker for immune responses in broiler chickens.
• MHC allele profiling can support vaccine design and genetic improvement for disease resistance.
• Understanding MHC polymorphism aids in resource conservation for commercial broiler production.