Genetic and phenotypic correlations between feather pecking behavior, stress response, immune response, and egg quality traits in laying hens

The objective of the current study was to estimate genetic and phenotypic correlations among feather pecking (FP) behavior and stress response, immune response, and egg quality parameters. These traits have been measured in an F-2 cross, coming from a cross between a high and a low FP line of laying hens. Heritabilities (h 2) of stress response (32 wk), primary immune response to keyhole limpet hemocyanin (KLH) (36 wk) and Mycobacterium butyricum (39 wk), and egg quality parameters (35, 44, and 50 wk of age) were calculated. The h 2 was 0.05 +/- 0.05 (SE) for stress response, 0.15 +/- 0.07 for antibody response to KLH, and 0.08 +/- 0.06 for antibody response to M. butyricum. The h 2 for egg quality traits were in the range of 0.12 to 0.30. Significant phenotypic correlations were found between gentle FP in adult hens and stress response, egg weight at 44 and 50 wk, and egg deformation at 50 wk. Significant additive genetic correlations were found between severe FP in adult hens and antibody response to KLH (0.79 +/- 0.35), and between ground pecking in adult hens and egg deformation at 50 wk (0.63 +/- 0.26), and between ground pecking and eggshell strength at 35, 44, and 50 wk of age (-0.86 +/- 0.29, -0.81 +/- 0.20, -0.76 +/- 0.24, respectively).