Relationship between production factors and dominance in White Leghorn hens in a study on social rank and cage design

Abstract

The effects of social rank and cage shape on feeding frequency, weight gain, production rate, egg size, shell strength and overt aggressive activity were determined for White Leghorn layers housed six per cage in deep and shallow cages. Social rank significantly affected feeding frequency, production rate, egg size, and aggressive activity for birds in both cage designs. Birds ranking high in the social order fed more frequently, had higher production rates, larger eggs and delivered more aggressive head pecks than birds low in the peck order. The effect for production rate was manifested only at the sixth bird level. Significant social rank effects on weight gain, final body weight and shell strength were not observed. Birds in shallow cages fed more frequently, gained more weight and were involved in more aggressive acts with cage mates than those in deep cages.