Modern commercial turkeys have been selectively bred to grow so fast and large that many cannot walk, mate naturally, or live without significant health interventions.
The bodies of commercial turkeys have been engineered for meat yield in ways that cause chronic pain and dysfunction. Leg deformities make walking painful, causing birds to spend most of their time lying in litter. Breast meat growth so exceeds leg strength that some birds cannot support their own weight. Cardiovascular strain from rapid growth causes cardiac failure. These are not side effects of farming but design features of breeding programs that prioritized growth metrics over animal health and welfare.