The billions of doses of antibiotics administered to farm animals are accelerating the rise of drug-resistant superbugs and undermining our most vital medicines.
International researchers warn that, without significant changes, global antibiotic use in livestock could surge by 29.5% over the next 15 years, driven by growing demand for animal products and an expanding human population. Their report indicates that under a business-as-usual scenario, global antibiotic use could reach about 143,481 tonnes by 2040, an increase from the 2019 baseline of about 110,777 tons.
The findings were published in Nature Communications.
Misuse of antibiotics
The overuse and misuse of antibiotics in livestock has contributed significantly to the emergence of antimicrobial resistance, which renders antibiotics ineffective, putting vulnerable populations—especially those with limited access to healthcare—at increased risk of numerous infectious diseases.
Globally, approximately 70% of antibiotics are fed to farm animals. An estimated 70% of these drugs are excreted and enter the environment, affecting soil, water, and ecosystems, which in turn elevates the risk of antibiotic resistance.
The World Health Organisation has called on the agriculture sector to cease the routine use of antibiotics to promote growth and prevent disease in healthy animals.
There is a lack of regulation on the antibiotics used on livestock compared to human medicine.
“On a global scale the types that are frequently used, for instance, third-generation cephalosporins and fluoroquinolones – are last-resort types of antibiotics in people yet are used routinely in a lot of countries in food animals,” says Peter Collignon, an infectious diseases physician and microbiologist, and a professor of microbiology at the Australian National University. Collignon was not involved in this research.
“The biggest risk area is usually in Asian countries because there’s a lot of antibiotic resistance already there.” says Collignon. “If you get even more resistant bacteria developing in food animals because you’re giving them too many antibiotics, then those superbugs get into the rivers and then into people via foods and water.”
Collignon says transparency in antibiotic usage remains critically lacking in Australia.
“We often have no knowledge of what antibiotics are used here in food animals and farmed fish.
“Can we readily get that data? No. It’s all secret information kept by the government and industry. Industry often says it’s because we don’t want our competitors to know. The competitors know all about it. Who doesn’t know? Just consumers and those interested in protecting public health.”
The researchers say moderate reductions in antibiotic use intensity (the frequency and duration of antibiotic treatment) and fewer, more productive livestock could offset this overall increase.
Alternative projections suggest that reducing antibiotic use per animal by 30%, along with lowering total livestock numbers through productivity improvements, could prevent overall antibiotic use from increasing.
The most significant reduction would come from a 50% decrease in antibiotic use per animal, combined with fewer livestock, which could cut total antibiotic use by nearly 57%, bringing it down to around 62,000 US tonnes per year by 2040.
Antibiotics losing their effectiveness
