The effects of stocking density on the growth, behaviour, and welfare of layer pullets in two cage systems
The objective of this research was to examine the effect of stocking density (SD) on growth, behaviour, and welfare in 1.) conventional (274-342 cm2/bird) and 2.) furnished (247 335 cm2/bird) rearing cages. SD was adjusted by altering group size. In conventional cages, stocking density significantly affected bodyweight; pullets from lower densities were heavier than those from high densities. Rearing density did not affect feeding behaviour, feather pecking, or aggression. The effect of SD on bodyweight was inconsistent in 3 strains of pullets reared in cages furnished with perches and a platform. Locomotion decreased as stocking density increased, while most other behaviours were unaffected. The proportion of birds perching at night from high densities declined as birds grew, suggesting that perch space became limiting. The results of this project indicate that stocking density may affect growth, the ability to locomote, and night perching, but this is likely dependent on cage design.