Selective breeding for rapid growth has created severe welfare problems in broiler chickens. The science of slower-growing breeds demonstrates that welfare and production outcomes can be dramatically improved.
The welfare problems of fast-growing broiler breeds are systemic, not management failures — they arise directly from the genetic modification that produces rapid muscle growth at the expense of skeletal and cardiac development. Broilers bred to grow at over 60g/day develop breast muscles so large that the birds cannot stand, walk, or reach food and water without pain and difficulty. Research comparing fast and slower-growing breeds consistently shows that slower breeds have better gait scores, lower mortality, more active behaviour, and higher positive welfare indicators. Stocking density interacts with breed: even slower-growing birds show poor welfare at very high densities. The Better Chicken Commitment criteria — slower-growing breeds, lower density, enrichment, and improved slaughter — represent the current evidence-based benchmark for commercial improvement. Producer adoption is growing but remains far from universal, making consumer and retailer pressure essential.