Each year, around 36 million birds die in the sheds before reaching slaughter age. Many of these deaths are caused by heart and lung diseases and disorders. Most chickens are killed between the ages of 6 - 7 weeks. They now reach slaughter age twice as quickly as they did 30 years ago. Most of the heart and lung problems are caused because the birds are growing so fast, many die from heart failure.
Lameness is another problem related to such rapid growth.
So the legs have to support a great weight. Once at slaughter weight, the birds are caught up and transferred to crates on the back of lorries. Wings and legs are often trapped when they are being pushed into cages. Each year, between one and two million birds die on the way to the slaughterhouse. These deaths are caused by injuries, suffocation and shock.