By 2050, global infectious disease caused by antibiotic-resistant bacteria is projected to be responsible for 10 million human deaths per year—1.8 million more than cancer. Antibiotic resistance is a natural phenomenon, but the anthropomorphic use of antimicrobials has created heightened selective pressure that has led to an increased presence of antibiotic-resistant bacteria in agriculture, aquaculture, and hospital environments. Concerns over the emergence of antibiotic-resistant bacteria that threaten human health has prompted the retail and fast food sector to promote meat and milk produced from livestock that are raised “without the use of antibiotics.” Antibiotics have become an integral component of intensive livestock production and are used to treat (therapeutic use) and prevent (prophylactic, metaphylactic) infectious disease and promote growth (subtherapeutic). The growing restriction of antibiotic use in livestock production has promoted research into a plethora of potential alternatives.