Research Note: Differences in Major Histocompatibility Complex Gene Frequencies Associated with Feed Efficiency and Laying Performance

Associations between egg production and feed efficiency and the genes of the major histocompatibility complex (MHC) of the chicken were investigated. Breeders were selected on the basis of indexes incorporating information on body weight and egg mass, with or without feed consumption information. Over 1,000 progeny were serotyped for the erythrocyte antigen B (Ea-B) after the 6th generation of selection. The B2 and B13 haplotypes accounted for over 75% of the Ea-B gene pool in all lines. Comparing each index-selected line with the control B2 significantly increased in frequency at the expense of B13. This study further implicates MHC-linked genes as important in the physiology of growth and reproduction in the chicken.