Imprudent Use of Antibiotics in Livestock Production

It is common knowledge that various antibiotics used to promote growth or treat diseases in livestock are also used in human medicine. There is increasing scientific evidence that resistant bacteria can develop as a result of misuse of such antimicrobials. Resistant bacteria can be transferred from animals to humans, resulting in infections that are harder to treat.

Reports of antibiotic-resistant infections in hospitals across the world have been increasing every year, and the question has been raised as to how this escalation of resistance could have been influenced by the use of antibiotics in livestock production.

It is now irrefutable that the imprudent use of antibiotics has led to the selection of resistant bacteria. Although the entire process involves various factors, the scope of the emerging problem depends mainly on two criteria, which is the duration of exposure to the antibiotic and its concentration.

There are currently three main functions for antibiotics in livestock production. Antibiotics may be used at subtherapeutic doses for growth promotion, prophylactically for disease prevention, or therapeutically for disease treatment.

However, recent statistics have shown that most antibiotics used in agriculture today are applied to livestock animals through their feed at subtherapeutic doses. Thus, they are used as growth promoters. They act by suppressing harmful microorganisms and increasing gut health, which leads to improvements in feed conversion efficiency, optimisation of genetic potential for growth and reduction of waste product output from intensive livestock production.

Adverse consequences of such imprudent use of antibiotics include an increase in the prevalence of resistant bacteria in animals and the transfer of these pathogens to humans via direct contact with the animals, or through consumption of contaminated food or water. The transfer of resistance genes from animal pathogens to human ones is also possible and this will increase the incidence of human infections caused by resistant pathogens, leading to potential therapeutic failures in both animals and humans.

Various steps can be taken to improve the situation. The use of any antimicrobial agent for growth promotion in animals should be terminated if it is also used in human therapeutics, or known to for cross-resistance to antibiotics used in human medicine. National authorities should monitor for inappropriate use of antibiotics in livestock production to ensure only judicious use of such substances. Increased concerns regarding risks to public health resulting from the use of antibiotic growth promoters indicate that it is essential to have a systematic approach towards replacing such antibiotics with safer natural alternatives.

Many producers fear that once they stop using antibiotics, farming will become more complicated and costly. But what are the costs of feeding antibiotics to livestock? For eighty years, humans have been able to fight life-threatening infections. The misuse of antibiotics looks set to destroy these profound benefits to human health within less than a century of its discovery. Should we really be gambling with these last silver bullets?