http://www.keepantibioticsworking.com/new/index.cfm

An intersting website that focuses on the use of antibiotics as feed
additives for livestock and poultry – not to treat disease, but
instead to promote growth and compensate for crowded, stressful,
unsanitary conditions.
"Antibiotic use in animal agriculture has been linked definitively
to human bacterial infections resistant to antibiotics. Mounting
evidence suggests that widespread overuse of agricultural
antibiotics also may be contaminating surface waters and
groundwater, including drinking water sources in many rural areas.
Nonetheless, agribusiness and the pharmaceutical industry are
fighting hard to thwart restrictions on the use of antibiotics in
agriculture. "