Evolution of Bacteria

“Most of the antibiotics given to livestock aren’t used to treat illness but to quicken the animals’ growth or as a preventive measure to keep disease from sweeping through the crowded pens and cages that are common to industrial agriculture.” -Los Angeles Times
Using antibiotics has been a concern for humans for a while. It is preferred that we don’t use them too often or use too many because of the possibility of developing a “super bacteria”. Basically, when we use antibiotics there are some bacteria that are immune to them who survive and multiply. There is plenty of scare for what that means in the future. It’s possible the antibiotics we know could be rendered useless as all of the surviving bacteria will be immune.
If this is the case, why is it that we rely so heavily on antibiotics for our livestock? We care about the use of antibiotics for human use, but according to an article in the Star Tribune, “three-fourths of the antibiotics in this country are used on livestock”.
It is becoming apparent that we only spend time worrying about certain sides of current problems, but what will that cost us in the future?