Chicken welfare is influenced more by housing conditions than by stocking density

Intensive broiler (meat) chicken production now exceeds 800 million birds each year in the United Kingdom and 2 × 1010 birds worldwide1, but it attracts accusations of poor welfare2,3. The European Union is currently adopting standards for broilers aimed at a chief welfare concern—namely, overcrowding—by limiting maximum ‘stocking density’ (bird weight per unit area). It is not clear, however, whether this will genuinely improve bird welfare...