Mapping of Quantitative Trait Loci Affecting Growth Traits in a Japanese Native Chicken Cross (Report‪)‬

INTRODUCTION In poultry, many QTL mapping studies have been performed on breed crosses, e.g. broiler x layer (Sewalem et al., 2002), Red Junglefowl x White Leghorn (Kerje et al., 2003), White Leghorn x Rhode Island Red (Sasaki et al., 2004), and broiler x White Leghorn (Schreiweis et al., 2005). This approach has proved very successful in identifying QTLs that explain differences between these breeds; however, they provide no insight into whether these QTLs would be useful for breeds/lines other than the founder breeds used in the respective QTL studies. Therefore, studies using crosses between divergently selected lines within a breed are becoming popular for their potential contribution to the improvement of growth traits in broilers (Jacobsson et al., 2005; Ankra-Badu et al., 2009; Wahlberg et al., 2009) and eggshell traits in the White Leghorn (Takahashi et al., 2009, 2010; Yang et al., 2010). Moreover, there are few studies that described QTLs for growth traits within a native chicken breed.