A Brief Guide to Antibiotics in Farming

Antibiotics are the bedrock of modern farming systems. But what effect is this having on our natural environment, human health and animal well-being? And should we do something about it?

For decades, antibiotics have been used in animal farming to treat infections, protect the health of livestock and stimulate growth. They have facilitated the growth of intensive animal production and allowed global food systems to meet the rising demand for animal protein.¹ But today, around 80% of all antibiotics are given to animals.^{2, 22}

And our dependence on antibiotics isn’t showing signs of slowing. Current trends suggest the use of antibiotics in farming is increasing and is expected to rise by 8% globally and 5% in Europe between 2020 and 2030.¹

But while the general trend remains upward, recent years have seen a strong push to dial back usage. In 2022, the EU banned the routine use of antibiotics in farming, including preventative use, unless absolutely necessary.^{3, 23} Before jumping into eight promising solutions to antibiotics in farming, let’s briefly go over why antibiotics can be a problem.

Negative effects of antibiotics in animal farming

The overuse of antibiotics in animal farming contributes to environmental pollution, facilitates intensive farming systems with poor animal welfare and fuels the evolution of drug-resistant bacteria, with alarming consequences for human health. Here are a few key effects of mismanaged antibiotic use in livestock farming.

Environmental pollution

EU laws require that meat, dairy or eggs must not have residue levels of antibiotics (and other veterinary medicines) that represent a hazard to human health.⁴ However, this does not prevent synthetic antibiotics in animal manure from contaminating the surrounding soil and nearby water sources or drug residue excreted by humans from reaching aquatic environments.⁵

This can have devastating effects on wildlife. For example, once excess antibiotics have been excreted by animals, the resultant pollution can damage developmental, cardiovascular and metabolic systems in fish as well as alter their immune responses.⁵

A tank truck spreading manure on a recently harvested corn field. In Europe, animal farming generated annually more than 1.4 billion tonnes of manure between 2016–2019, which more than 90% is directly re-applied to soils as organic fertiliser, but if polluted it can introduce heavy metals, and antibiotics to the soil. (Getty Images)

Decrease animal welfare

In many ways, antibiotics are beneficial for animal welfare. After all, farmers need to take good care of their animals, including veterinary treatment, when they get sick. But in some cases, antibiotics have been used to prop up intensive farms.⁷

Preventative, or prophylactic, antibiotics have routinely been given to whole herds living in intensive farms, where disease outbreaks are common and harder to control due to overcrowded and unsanitary conditions.^8,9

The use of preventative antibiotics was banned by the EU in 2022, in theory forcing livestock farmers to move away from intensive farming systems associated with high antibiotic use.⁹

However, the European Public Health Alliance has warned of widespread non-compliance with the legislation because there is little indication that farmers are making this change.¹⁰

Undermining modern medicine

While antibiotics are considered the foundation of modern medicine, the overuse of antibiotics in animal farming is a major driver fuelling the evolution of drug-resistant bacteria, rendering some antibiotics ineffective for both animals and humans.^1,11

In 2017, the World Health Organisation warned that “some types of bacteria that cause serious infections in humans have already developed resistance to most or all of the available treatments, and there are very few promising options in the research pipeline.”¹²

Already, 700,000 people a year die from diseases which antibiotics cannot treat. By 2050, the UN estimates that the figure will rise to 10 million deaths, matching the global death toll of cancer for 2020.¹³

8 Ways to reduce antibiotics in agriculture

It is unlikely that we will ever be able to create animal farming systems without antibiotics or reverse all the damage already done.⁷ But there are ways we can create a more sustainable future for antibiotics.

“Instead of introducing new antibiotics into the old system - possibly leading to the emergence of more drug-resistant bacteria - we must change the system to one that does not create conditions in which infections can thrive,” Dr Lance G. Price, Director of the Antibiotic Resistance Action Center at George Washington University, told FoodUnfolded.

Here’s what that might look like:

1. End intensive farming

Intensive farming can lead to overcrowding, lack of proper sanitation, high stress and lower-quality feed. This environment fuels the spread of disease and, therefore, the evolution of drug-resistant bacteria.

“We know that crowding people makes them sick. I wouldn’t be happy living in a crowded space with other people and defecating on the floor. Why do we turn off our brains when it comes to animals?” Dr Price said.

Reducing stock density and placing stringent controls on hygiene and environmental conditions that help reduce stress would reduce the need for antibiotics.⁷ For example, organic systems in the UK require farmers to keep piglets with their mothers for at least 40 days after birth, compared to 21-28 days in intensive systems.¹⁴ This reduces the stress of separation and improves both the piglet survival rate and the health of adult pigs.¹⁴

According to the Soil Association, a study found that non-organic pig farms used between 13-330 times more antibiotics than organic.¹⁴

Changing population dynamics and cleaning up animal hygiene would reduce the speed at which infections spread through the entire herd, reducing our dependence on preventative antibiotics.

2. Optimise feed and nutrition

Improving feed quality and using probiotics to encourage the growth of good bacteria in the gut can also promote good health, reducing infections and, therefore, the need for drugs.

Feeding animals the right type and optimal amount of feed - for example, feeding cattle low-energy diets instead of cheap, high-energy, starchy diets, which led to live abscesses - would reduce the need for antibiotic intervention.¹⁵

A nutritious diet can also enhance an animal’s natural immunity.

3. Breed genetically disease-resistant livestock

Scientists today can alter animal DNA and breed animals with favourable genetics - such as disease-resistant livestock.

Traditional selective breeding has not targeted disease resistance and advantageous production traits at the same time, but alternatives are being developed which will make this possible.⁷

However, this is still not allowed in the EU, and it is considered a long-term solution given the ethical, environmental, and social implications. If it is to be part of efforts to reduce the use of synthetic antibiotics, it must also be cost-effective for farmers.¹⁶

4. Eradicate specific diseases

Eradicating diseases reduces the need for antibiotics because farmers no longer have to treat those infections. This approach becomes a viable option when the illness also poses an extreme public health risk, such as tuberculosis and brucellosis.⁷

Sadly, this eradication is often done by slaughtering the entire herd of animals, and it can also have a huge impact on wildlife. For example, over 200,000 badgers have been culled in the UK since 2013 to try to control bovine Tuberculosis, an infectious respiratory disease which affects cattle.²⁴

Such diseases can also be tackled through vaccination programmes, which are increasingly becoming the norm.²⁵

5. Plant medicine

Where diseases cannot be eradicated, farmers can seek to use medicinal plants and their extracts to effectively treat infections in livestock.

Unlike synthetic antibiotics, it is difficult for bacteria to develop resistance to the multiple and complex phytochemicals present in plant extracts.¹⁷ This means that medicinal plants can reduce the overall use of synthetic antibiotics while at the same time preventing antimicrobial resistance.

And whereas synthetic antibiotics can cause pollution, there is no evidence that medicinal plant extracts in animal manure contaminate the surrounding soil or nearby water sources.

6. Phage therapy

It’s not just plants that could become an alternative to antibiotics, phage therapy is also an option.

Bacteriophages, viruses which multiply in specific bacterial cells and kill them, can be used to treat bacterial infections. (Farmers can inject animals with bacteriophages rather than antibiotics.)

But it’s too early to say how effective this might be at scale. Research is ongoing into whether bacteriophages present a real solution to drug resistance caused by overuse of antibiotics.¹⁸

7. Policy change

Governments and international organisations could make binding commitments to raising animals with minimal antibiotic use and introduce higher bars for giving antibiotics to animals. But we need to keep these commitments linked to what’s happening on the ground. Real-time monitoring of antibiotic use on animal farms will be key to effecting change and allow for troubleshooting when drug use increases.

Scandinavian states, particularly Denmark, have led the way in monitoring, leading to policy changes that have greatly restricted the use of antibiotics in animal farming.^19,20 And the results are promising. Data from the project showed that reducing the quantity of antibiotics used in animal farming led to a decrease in the number of drug-resistant pathogens in animals and humans.²⁰

8. Market pressure

There’s also an opportunity for market-based strategies, where consumers put pressure on producers and restaurant chains to stop buying animals that have been fed antibiotics.

For example, Chik-a-fil, an American fast food chain, switched to antibiotic-free chickens after a food blogger wrote about their use of controversial ingredients.²¹

This goes to show how pressure from consumers can pressure retailers to change suppliers for animals that have had low or no exposure to antibiotics. If enough retailers are affected, this could force farmers to change their practices, too.

“Policy makers and consumers will have to force the hands of the pharmaceutical companies and farmers themselves,” Dr Price told FoodUnfolded.

“If you’re not forcing the hand, then nobody is going to do it. Ideally, every country steps up and changes its policy to recognise the value of antibiotics to humanity and says we are going to do all we can to protect them.”