Since their discovery, antibiotics have been instrumental in treating infectious diseases that
were previously known to kill humans and animals. However, their widespread use as an
additive in animal feeds has raised concerns about the development of antibiotic‐resistant
microorganisms. Increasingly, more microorganisms are becoming resistant to multiple
antibiotics. A high proportion of the antibiotics added to animal feed is excreted in urine or
manure. In some cases, as much as 90% of the antibiotic administered orally may pass …