Comparison of Empirical and Theoretical Responses to Selection Against Mortality due to Cannibalism in Layers

Abstract Text: Genetic improvement of socially-affected traits, such as mortality due to cannibalism in layers, requires a selection method that takes indirect genetic effects (IGEs) into account. Moreover, the selection method needs to be applicable in commercial poultry breeding, where selection candidates are housed individually. Previously we proposed ‘selection based on relatives in family groups’ as a practical method to improve socially-affected traits in commercial poultry breeding. We also presented estimated genetic parameters for survival in White Leghorns, which allows theoretical prediction of response to selection. Here we compare empirically obtained results of this selection method to theoretically predicted responses to selection for survival in layers. Expected responses were small (1.3 to 5.0 days), because selection intensity was small. In generation 5, realized response between high survival and control was negative. In generation 1 and 6, selection resulted in realized responses of 13 and 19 days.

Keywords:

Survival

Layers

IGEs