Social behaviour of domestic animals II. Effect of the peck order on poultry productivity

SUMMARY 1. Peck order position was assessed by aggressiveness scores for birds housed intensively on deep litter on the floor and in cages. 2. Relationships were shown between scores and egg weight, egg number and egg mass for the birds on the floor but not for the caged birds. The nature of the relationships found was discussed. 3. The correlation between egg weight and egg number was higher in the flock on the floor than in the caged flock. This appeared to be due to a significant positive correlation among the lowest scoring birds on the floor.