"Confinement at high stocking density is one part of a systematic effort to produce the highest output at the lowest cost by relying on economies of scale

"Confinement at high stocking density is one part of a systematic effort to produce the highest output at the lowest cost by relying on economies of scale, modern machinery, biotechnology, and global trade. Confinement at high stocking density requires the use of antibiotics and pesticides to mitigate the spread of disease and pestilence exacerbated by these crowded living conditions. In addition, antibiotics are used to stimulate livestock growth by killing intestinal bacteria." -- http://en.wikipedia.org/wiki/Factory_farming http://en.wikipedia.org/wiki/Factory_farming An even better article is on the German Wikipedia: http://de.wikipedia.org/wiki/Intensivtierhaltung#Antibiotikaresistenzen http://de.wikipedia.org/wiki/Intensivtierhaltung#Antibiotika...