It’s difficult to quantify absolutely. Farmers have used antibiotics to promote growth and increase health. When they’re used in healthy animals it can increase resistance (susceptible ones die and resistant survive and grow) and these resistant bacteria can make their way into the wider environment. Europe banned the use of antibiotics for growth promotion in 2006 and this has helped to decrease resistance detected in animals. Medically important antibiotics can’t be used for this now so there’s a smaller reservoir for developing resistance and hopefully less coming through into healthcare situations.
Such an important and timely question! thank you.
the effect of use of antibiotics in animals and livestock is enormous. Following Europe such misuse of antibiotics (growth promoting factors) in farming should be banned worldwide! Also to note that transmission of antibiotic resistance from animal/ live stock to human (vice versa) is identified in large numbers!!