The United States is the world’s largest turkey producer and the largest exporter of turkey products. Its residents also consume an ever-increasing amount of these birds. In 1970, Americans ate just over 8lbs (3.6kg) per person annually; by 2021, the National Turkey Federation reports that figure had nearly doubled to more than 15lbs.

That demand and modern breeding have transformed turkeys. They’ve been bred to put on weight quickly, and at slaughter, the average turkey today weighs almost twice as much as turkeys did in 1960. The contrast with the rate of growth of wild turkeys is even greater. At four months old, a male wild turkey will weigh no more than 8lbs, whereas at the same age, a male turkey selectively bred for meat will weigh 41lbs.

That puts an enormous strain on their immature leg bones. Professor John Webster, a veterinarian and expert on the welfare of farmed animals, has studied a similar problem in fast-growing chickens and concluded that they are in pain for the last third of their lives – a situation that has been compared with forcing someone with arthritis in their legs to stand up all day long.