Fearful and Associated Responses of Caged White Leghorn Hens: Genetic Parameter Estimates ,

Data were obtained from hens kept in three-bird cages in two, full-year experiments. Feather damage and loss scores, several fear-indicating variables, and measures of egg production were analyzed to obtain estimates of heritabilities and genetic and phenotypic correlations. Heritability estimates were slightly biased because data on individual hens were not available for most traits. Heritability estimates of productivity traits were fairly consistent with values obtained by others, except for age at sexual maturity, which was exceptionally low. Estimated heritability of egg number, based on a 15-day palpation period following full-year egg production, was also low. Feather score appeared to be moderately heritable. Heritability estimates involving escape and avoidance behavior and duration of induced tonic immobility indicate that those fear-related traits should respond to selection, if measured appropriately. None of the correlation coefficient estimates involving associations among feather scores, fear-inducing variables, and measures of egg production differed significantly from zero.