Mapping of QTLs Controlling Egg Quality on Chromosomes 6-8, Z and Three Linkage Groups in Chickens

Two breeds of chickens were used to develop reference family and detect QTLs affecting egg quality traits: cocks of a native Polish breed Green-Legged Partidgenous (GlP) and hens of Rhode Island Red (RIR). During the first 100 days of the laying period, the GlP hens lay about 40 eggs weighting on average 50 g, whilst the RIR flock laid 83 eggs with a mean weight of 60 g. QTL analysis of egg quality traits was performed on 552 birds of the F2 generation with the aid of 19 microsatellite loci on chromosomes 6, 7, 8, Z and linkage groups 9 (E 36), 19 (E 52) and 26 (E 46). Linkage analysis was performed for 19 microsatellite markers within the mapped population and ten QTLs were found to affect seven egg quality traits: at week 53-shell thickness, shell strength, albumen weight, egg specific gravity and percent of yolk in egg; and at week 33-percent of yolk in egg and Hugh’s units.