Slow-growth broiler breeds (daily gain <50g) show substantially better welfare outcomes compared to fast-growth conventional breeds (daily gain 60-70g). Research confirms slower-growing birds have lower leg disorder prevalence (15-20% vs 35-50%), better gait scores, reduced ascites risk, and higher activity levels. The Better Chicken Commitment (BCC), signed by hundreds of food companies, mandates transition to slower-growing breeds by 2026. Major fast food and retail companies have made commitments covering billions of birds. Economic analysis shows premium cost of 3-5p per kg live weight is achievable with market differentiation. Breed options include Hubbard JA757, Rambler Ranger, and Rowan Range certified strains. On-farm enrichment (perches, natural light, pecking objects) combined with slow-growth genetics produces the strongest welfare profile.