antibiotics in poultry

Hello, sanet-ers.
I'm doing some research on the use of antibiotics in poultry production
and the risks to human health of residues in poultry products.  For those
of you who may raise organic/free-range poultry without the use of
antibiotics, I'd like to get some feedback on a few questions:

1. Why do you not use antibiotics?
2. What do you use/do instead to prevent and treat diseases?
3. If you have experience using antibiotics in past, what has been notable
differences in the health of your chickens, quality of product etc, or is
there any way to measure this?

I welcome other people's comments on the use of antibiotics in
poultry regarding what you know about the use of antibiotics, if you think
there is a health risk to humans or if systems for monitoring drug
residues in poultry is adequate for public safety.

Thanks in advance.

Loren Fisher
Tufts University 
School of Nutrition Science & Policy