Why are antibiotics used in feedlots?

In feedlots, antibiotics are used for several primary purposes, often administered through feed, water, or injection.12

• Disease Prevention and Treatment: Due to high animal density, the accumulation of waste, and the health risks associated with grain-based diets, feedlots are ideal environments for pathogenic bacteria. Antibiotics are used prophylactically to prevent the spread of common bacterial diseases and to manage specific conditions like bovine respiratory disease.31
• Growth Promotion: Antibiotics are frequently administered in low, subtherapeutic doses to enhance animal performance, specifically by improving weight gain and feed efficiency.32

While these practices are intended to support animal health and economic efficiency, they raise significant ethical and public health concerns. The widespread use of antibiotics in livestock is a primary driver of antibiotic resistance, which threatens the efficacy of medicines used in human and veterinary care. Because this practice risks global health, the World Health Organization advocates for restricting the use of medically important antibiotics in food animals and ending their use for growth promotion in healthy livestock.31