General combining ability of egg production traits of broiler lines using principal components analysis

This study was conducted using data from single crosses (diallel) withim three female lines (PP, KK and VV). A completely randomized block design, with 81 single crosses treatments, three replicales with 81 broilers was used. The twelve production traits were: egg number during the periods of 24(th)-32(nd), 32(nd)-40(th), 40(th)-48(th), 48(th)-56(th), 56(th)-64(th), 22(nd)-66(th), 32(nd)-66(th), 40(th)-66(th), 48(th)-66(th), 24(th)-40(th), 24(th)-48(th) and 24(th)-56(th) weeks of age. The first two principal components explained more than 98% of total variance of the crosses means. In the study of the general combining ability (GCA), based an the scores of the first two principal componentes, the parent lines PP and VV were selected by GCA, for principal component1, however for the principal component 2 the parent line selected was PP.