Some health challenges, such as the COVID pandemic, clearly demonstrate the importance of a considered, global response. Maintaining high levels of human and animal health is possible because we have access to highly effective antimicrobial products for the treatment of bacterial infections. However, rising levels of antimicrobial resistance (AMR) are amplifying concern over the long-term efficacy of antimicrobials. Through a growing understanding of the link between antimicrobial use and the level of AMR, the global farming industry has implemented various measures to reduce antimicrobial use. The success of these measures and efforts is proudly presented here.

Efforts by various European countries have resulted in the reduction of antimicrobial use. The third joint inter-agency report published in 2021 by the European Centre for Disease Prevention and Control provides an integrated analysis of antimicrobial agent consumption and the occurrence of AMR in bacteria from humans and food-producing animals. Data used in the report was gathered from 27 European countries between 2016 and 2018.

Antimicrobial consumption by farm animals decreased

The report provides an integrated analysis of possible relationships between antimicrobial consumption in humans and food-producing animals and the occurrence of AMR in bacteria from humans and food-producing animals. It clearly demonstrates that, for the first time since 2011, overall antimicrobial consumption was lower in food-producing animals than in humans.

For the first time since 2011, overall antimicrobial consumption was lower in food-producing animals than in humans

This change is the result of a significant decrease in antibiotic usage among food-producing animals, suggesting that the country-level measures implemented to reduce antimicrobial use in food-producing animals are effective.

In 2021, the FDA (Food and Drug Administration) also published a report indicating a reduction in sales of antibiotics to animals in the US. Domestic sales and distribution of medically important antimicrobials approved for use in food-producing animals decreased by 28% from 2016 to 2020 for all producing animals, and by 72% for chickens.

Large animal producing regions that do not monitor antibiotic use and resistance have successfully implemented regulatory restrictions for antibiotic use in farm animals. Additionally, the will of animal protein producers to satisfy customer desire for antibiotic-free production strongly contributed to the reduction of antibiotic use.

Antimicrobial resistance in farm animals decreased

It is empowering to observe the success in reducing antibiotic use in farm animals. Regions using high levels of antimicrobials are motivated and confident to continue this reduction further. The main contribution to improving healthcare that these efforts provide is a reduction in AMR, ensuring antimicrobial activity remains effective.

A reduction in AMR ensures antimicrobial activity remains effective

Does reducing antimicrobial use lead to the reduction of AMR? The resistance of different antimicrobials has been monitored for many years in some countries. Data from the US demonstrates that the reduction of antimicrobial use in chickens leads to a reduction in AMR (Figure 2). Similar trends are observed for other countries.

What was driving success?

Alexander Fleming presciently warned about the dangers of misusing antibiotics in his Nobel lecture in 1945: “It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them, and the same thing has occasionally happened in the body.” After some years of extensive antibiotic use, surveillance of AMR in bacteria from human isolated bacteria provided very clear evidence of the AMR problem on a global scale.

In the past, the use of antibiotics was higher in animals than in humans. Therefore, the need to reduce antibiotic use in animal production was clearly recognized. Sweden banned the use of antibiotic growth promoters (AGPs) in 1986 and other countries have since followed.

The surveillance of antimicrobial use and resistance in farm animals was established in different countries and the success of reducing antimicrobial use and its impact on AMR in recent years has become evident. Clearly, measurements were contributing to the success, but the main success driver was the reduction of antimicrobial use on the farm. Animal protein producers were able to improve biosecurity, farm management, and nutritional strategies, and increase the use of alternatives to antibiotics to prevent diseases.

The main success driver was the reduction of antimicrobial use on farm

Alternatives to antibiotics

Antibiotics are used in three principal ways in animal production:

1. Growth promotion - Antibiotics or so-called AGPs are administered to healthy animals to make them grow faster. Alternatives for AGPs that have been confidently used in recent years include probiotics, organic acids, plant-derived products, and essential oils as well as digestive enzymes. The use of AGPs is banned in most large livestock producing regions. We know that alternative solutions are very effective and can be used as part of the comprehensive approach to the improvement of farm management processes.
2. Disease prevention - With two possible scenarios: prophylactic use – where there are no symptoms of disease but there is a risk of disease, or metaphylactic use – where the first signs of disease appear in some animals and antibiotics can be administered to all animals in the group to prevent the spread of disease. The most common alternative for disease prevention is vaccination for many animal species. To proactively combat digestive tract diseases, gut health products such as pro/prebiotics, phytogenics, organic acids, and immune modulators - antibodies for passive immune response, are used. Since 2022, the prophylactic and metaphylactic use of antibiotics in Europe has been restricted. Further restrictions will target the treatment of group animals and the use of critically important antimicrobials for human medicine.
3. Disease treatment - Antibiotics are administered during the presence of disease. There is no real alternative to an antibiotic for treatment of bacterial infections. This is why we need to ensure that antibiotics can remain effective for the treatment of humans and animals in the future.

Looking ahead to the brighter future

Further interventions to reduce antimicrobial use will continue to have a beneficial impact on the occurrence of AMR, which underlines the need to promote the prudent use of antimicrobial agents, infection control and prevention in both humans and food-producing animals.

The surveillance of AMR not only demonstrates the impressive success of animal producers to reduce antimicrobial consumption but also demonstrates the possibilities for further improvements. As shown in Figure 3, the prevalence of antibiotic-susceptible bacteria (those not resistant to antibiotics) can be as high as 80%, which is the current situation in Iceland, Finland, and Norway.

It will be very challenging or perhaps even impossible to achieve the antibiotic resistance prevalence of the pre-antibiotic era. However, a big reduction is surely possible for animal producers in many countries. Ensuring the efficacy of antimicrobials in the future and reducing AMR is possible and provides clear benefits for the health of animals and people.