>Fewer hormones for growth

>Chicken gets more exercise and movement

Having raised chickens for meat on a small scale (30-40 at a time), I can tell you that chickens used for meat ("Broiler" chickens) are selectively bred to grow as big as possible as quickly as possible. There is no need for growth hormones, they grow so quickly that their bone structure cannot keep up, to the point that they are barely able to walk 8-12 weeks from hatching. If they are not slaughtered on time, they die from heart failure.