Animal nutrition plays a significant role in reducing the need for antibiotic use by supporting overall animal health. A well-managed feeding program can improve productivity, reduce stress, and prevent an impaired immune system. Healthy, well-fed animals are less prone to infections, which represents the basis for decreasing the need for antibiotics.
Associate Professor in Animal Nutrition & Metabolism
TUM School of Life Sciences
Antibiotic resistance, which is addressed within the scope of the One Health approach, draws attention as a widespread problem worldwide. The extensive use of antibiotics in farm animals to support growth, prevent or treat diseases also contributes to the increase of this problem. For this reason, many countries, especially in Europe, continue to take important steps to limit the use of antibiotics and encourage responsible usage.
Professor Dr. Julia Steinhoff-Wagner from the Department of Animal Nutrition and Metabolism, School of Life Sciences, Technical University of Munich, is at the centre of many studies on antibiotic resistance. According to Prof. Steinhoff-Wagner, the most important way to limit the use of antibiotics is to keep animals healthy.
We discussed the cause and importance of antibiotic resistance, ways to limit antibiotic use without compromising animal health and productivity, and more in our interview with Prof. Dr. Julia Steinhoff-Wagner.
Ms. Steinhoff-Wagner, you are at the centre of a lot of research focused on antibiotic resistance. Firstly, could you tell us what antibiotic resistance is, why it has become such an important issue today and the contribution of livestock farming to antibiotic resistance?
Antibiotic resistance is defined as an ability of microorganisms to survive or grow despite the presence of inhibiting or killing agents that were previously effective against them. This resistance arises due to genetic changes in bacteria, either through mutation or by acquiring resistance genes from other bacteria.
For years, antibiotics were used in livestock farming for growth promotion or disease prevention. Since 2006 this is prohibited in Europe and only therapeutic use is allowed to reduce the development and spread of resistance. We are concerned about the effectiveness of treatments for us in the future and scared about untreatable pathogens. That is why we encourage the responsible use of antibiotics in livestock. Since infected animals need treatment, the most essential measure is to ensure that animals stay healthy.
Although there are very serious restrictions on the use of antibiotics in the EU and developed countries, their use continues extensively in many parts of the world. On a global scale, what are the most common reasons for the use of antibiotics in livestock farming?
While only therapeutic use is allowed in Europe, reasons worldwide include both therapeutic and non-therapeutic uses. Especially in poor hygiene conditions or very high stocking densities, antibiotics are often used in advance to prevent diseases. Another common use outside of Europe is growth promotion: I was shocked to hear at the animal science conference in the US that some researchers recommend the use of antibiotics to enhance growth rates and improve feed efficiency in livestock to make production more sustainable. This perspective of sustainability regarding resources does not fit our European one health approach.
How do antibiotic-resistant bacteria develop and spread? Can you explain the risk areas/regions?
Antibiotic-resistant bacteria develop through genetic mutations and the exchange of resistance genes between bacteria, often driven by the presence of a selector such as antibiotics or disinfectant agents. High-risk conditions include overuse or misuse of these active agents, poor hygienic management, particularly continuous housing systems, and high stocking density. Besides that, our research showed that feeding and drinking water hygiene are very important.
Is it possible to limit antibiotic use without compromising animal health, productivity and welfare? Can you explain at what stages, with what measures and support?
There is definitely potential to implement measures on practical farms further and improve animal health and welfare, resulting in less required antibiotic treatments. Some of these strategies can only be realized by monetary investments, and some lead to decreased productivity, such as reducing the stocking density or increasing vaccinations. Therefore, the value chain must cover additional costs to support farmers. Additionally, in some cases, we found in our research that there are still considerable knowledge gaps or attempts of trial and error that can be reduced by more intensive knowledge transfer, monitoring data analysis and exchange between farmers.
What is the role of animal nutrition, feed, and feed components in this process? To what extent can a well-managed feeding program, safe feed, and feed ingredients or correct feed formulation reduce the need for antibiotic use?
Animal nutrition plays a significant role in reducing the need for antibiotic use by supporting overall animal health. A well-managed feeding program can improve productivity, reduce stress, and prevent an impaired immune system. Healthy, well-fed animals are less prone to infections, which represents the basis for decreasing the need for antibiotics.
As already said, feeding and drinking water hygiene is a key aspect of keeping animals healthy, and this includes clean troughs and pipes without biofilms. Additionally, ensuring feed safety by avoiding contaminants like mycotoxins reduces the risk of illness.
A balanced ration with a desired composition of energy and nutrients also helps to maintain a strong immune system, reducing the likelihood of disease. Here, feed analyses following an animal-group specific feed formulation have not yet been carried out enough. If these basics are ensured, you can further optimize using feed additives, such as supplementation of probiotics and prebiotics. But I also recommend clearly identifying the aims of such measures and refraining from the more the better.
Could you tell us a little bit about the projects you are conducting (e.g. MiniAbeR), along with the objectives and content of these projects?
MiniAberR is funded as part of the model and demonstration projects (MuD) for animal protection in the federal livestock program. The funding comes from the Federal Ministry of Food and Agriculture (BMEL). It aims to minimize the use of antibiotics and the spread of resistance in poultry farming through knowledge transfer. My doctoral student wrote an extensive literature overview. The majority of field studies investigating the appearance of antibiotic resistance in poultry are very descriptive and seldom suggest specific measures to improve health.
On the other hand, studies investigating minimizing strategies were usually conducted under optimal conditions in research facilities. We found several topics where scientific knowledge is enormous but complex and knowledge transfer failed because scientific results do not result in feasible recommendations. Our task is to address this potential. One example is broiler bedding. From the literature, we know there is an optimal pH. There are many publications that show the influence of pH on animal health if the pH is too low and others if the pH is too high. And there are existing products on the market to change the pH, but we did not have a reliable method to check the pH of different bedding materials nor to have exact numbers to compare with. Therefore, we adapted VDLUFA methods from feed analytics to bedding and analysed many samples from farmers to get an overview of the status quo. This work will soon be published.
Can you give a brief overview of the data you have collected since the MiniAbeR project started in 2023? What kind of a picture do the results paint?
Everything else in the project is ongoing. We took samples from 11 farms and samples are currently processed in the lab. Unfortunately, we only have preliminary results from this sampling at this point. Our aim is to apply the suggested methods, protocols, or standard procedures and derive recommendations in combination with the resistance status of real farms. For this purpose, it would be helpful to have more farms participating. Due to the avian influenza, regrettably, the willingness to attend is limited.
