Modern broiler chickens have been selectively bred for such rapid weight gain that many suffer from cardiovascular failure, leg problems, and chronic pain before reaching slaughter weight, affecting over 60 billion birds annually.
The welfare crisis in broiler production is driven by a deliberate breeding strategy that prioritises growth rate over animal health. Broiler chickens with clinical lameness suffer chronic pain and have difficulty accessing food and water. Cardiovascular and respiratory problems from excessive muscle mass cause suffering and early death. High stocking densities limit natural behaviours and increase disease transmission, including avian influenza. Welfare science has established that slower-growing breeds on litter with natural light access show markedly better welfare outcomes across all measurable indicators.