The sad thing is, even animals that aren't sick are given antibiotics. Antibiotics, for some reason, also increase the rate at which animals grow and fatten up. So even healthy livestock get heavy doses of antibiotics. The same is often true for plants; antibiotics sprayed on plants sometimes increase growth. However, overuse of antibiotics also breeds strains of bacteria immune to them, which is really, really bad news for us. I don't think it is worth the 2 cent reduction in the price of beef, either.