Antibiotics with Chickens

I've found out that chickens are given a normal routine of antibiotics healthy our not. This worry's  me with the amount that is put in to these small animals. Truly chickens are not that big of animals and if they have a routine of antibiotics that gets put in to them might be to much for them and even for us who eat these animals. As I'm looking i found out the amount of the antibiotics causes it to become more aggressive. Witch the higher the stress the better chance of Campylobacter. Campylobacter is something that causes food poisoning in humans as well as abortion in animals. This has gotten 2.4 million people each year. The higher the stress the better chance of food poisoning and with s regular routine of antibiotics can cause stress witch then causes this food poisoning. As much as i want my chicken to be healthy  and good for me to eat their is a point to where it can be too much. This was something that got my attention when I was looking for info in this chickens and antibiotics.