Subtherapeutic Use of Antibiotics in Food-Producing Animals

Abstract The extensive use of antibiotics in food-producing animals has become controversial due to recent increases in resistant bacterial strains in humans. Antibiotics are used for disease prevention (prophylactic), growth enhancement, and treatment of disease (therapeutic). Both prophylactic and growth enhancement therapy are administered at doses which achieve plasma concentrations below therapeutic values. Unintentional subtherapeutic plasma levels of antibiotics are also achieved during therapeutic administration in feeds, due to factors which decrease absorption. This widespread subtherapeutic use of antibiotics has led to concern that such practices may contribute to the emergence of resistant strains of bacteria that propose risk to human health (11). A reevaluation of the extensive use of antibiotics in food-producing animals is needed. Do the benefits of subtherapeutic antibiotic use outweigh the potential risk to human health?