Quantitative genetic analysis of shank, keel, pubic and abdominal measurements in White Leghorn

The study was conducted on two selected and a control line of White Leghorn consisting a total 1753 pullets pedigreed by 106 sires. Selected strain PL2 had, in general, significantly higher shank diameter, abdominal span and pubic span than strain PL1. Keel length, abdominal span and pubic span of the selected strains were significantly better than the control prior to onset of laying, but during the laying period (32 and 40 weeks of age) the differences became non-significant. The heritability estimates were in general moderate for shank length (0.13–0.25), keel length (0.36–0.37) and shank diameter (0.07–0.34), but were generally low for abdominal and pubic span. There were no consistent differences in estimates between strains. Shank length at various ages has negative genetic correlation with egg number, egg weight, egg mass, efficiency index and positive with body weight at 20 and 40 weeks of age. Pubic and abdominal span at 16 weeks of age have highly positive genetic correlations with egg number, egg mass, efficiency index and moderate with egg weight. The results indicated that selection for genetic improvement of pubic and abdominal span at all the ages may be expected to improve egg number, egg weight and egg mass.