The selective breeding of broilers continued to the point that they are today bred to reach slaughter age in only six weeks, a rate of growth 300 per cent faster than in 1960. In that time, they reach a weight four times heavier on average than chickens raised in 1957. Chickens have suffered hugely as a consequence of this selective breeding, with many of them dying from organ failure, suffering from immune system problems and being unable to move due to their excessive weight, meaning they are unable to reach food and water points.
