How ATA (Alternatives to Antibiotics) can help Fight Antimicrobial Resistance

by Dr. Paolo Doncecchi, DVM

1. Context: Why Alternatives to Antibiotics Are Needed

The need to use ATA in livestock business stems from the misuse or abuse of antibiotics, which has contributed to the development of antimicrobial resistance and has increased pressure to reduce unnecessary antibiotic use in animal production. Evidence from systematic reviews indicates that interventions restricting antibiotic use in food-producing animals are associated with reductions in antibiotic-resistant bacteria in animals. [1]

In this context of growing rejection of antibiotic use in farming, alternatives to antibiotics should be presented not as isolated products, but as complementary tools within a broader health-management strategy. The objective should not simply be to replace one product with another, but to improve disease prevention, animal resilience, farm management and targeted veterinary intervention.

2. What ATA Include

First of all, when we talk about ATA (alternatives to antibiotics), we usually indicate a series of zootechnical tools ranging from the administration of vaccines, through the use of feed additives up to biosecurity.

Feed additives are divided into zootechnical and nutritional: when talking about alternatives to antibiotics, one immediately thinks of zootechnical additives such as additives against mycotoxins, probiotics, prebiotics, postbiotics, phytogenic compounds, organic acids, enzymes, peptides and bacteriophages. Several reviews describe these categories as among the principal approaches being investigated as alternatives to antibiotic growth promoters, although their efficacy can vary according to species, production system, pathogen, formulation and management conditions. [2,3]

However, it should not be forgotten that the use of the most traditional nutritional additives, amino acids, vitamins and trace elements, is also associated with animal physiological and immune functions. Nutritional status can influence intestinal integrity, immune response and the animal's ability to respond to infectious challenges. [4]

3. Stakeholders and Drivers of Adoption 

Secondly, the term "stakeholder" includes all the "actors" in the food chain, from the farmer to the final consumer, passing through regulatory authorities, international, national and local political authorities, veterinarians and their associations, breeders' and consumer associations, feed and pharmaceutical companies.

All stakeholders throughout the global supply chain know the possibility of using ATA products.

The difference lies in their use, influenced by public stakeholders (governments and regulatory bodies) who decide to prohibit or restrict the use of certain categories of antibiotics, particularly antibiotic growth promoters (AGPs), or by private stakeholders, represented by large-scale retail or "fast-food" groups that respond to health, safety and consumer expectations and therefore ask their suppliers of animal proteins to reduce or eliminate the use of antibiotics.

In the European Union, antibiotics other than coccidiostats and histomonostats were removed from the category of authorised feed additives from 1 January 2006. [5] China subsequently implemented a policy eliminating growth-promoting medicated feed additives other than traditional Chinese medicine products from 2020, while retaining certain therapeutic and anticoccidial uses under its regulatory framework. [6]

The action of private stakeholders is also well illustrated by the U.S. poultry sector. Published analyses have documented substantial reductions in antimicrobial use in broiler production, including major reductions in the use of several ionophores between 2013 and 2021. [7]

4. Vaccination as an ATA Tool 

Focusing on vaccination first: it is a well-established practice with the potential to reduce antibiotic use. Routine vaccination on the farm can improve control of specific infectious diseases and consequently reduce the need to intervene with antibiotics. A systematic review and meta-analysis found that vaccination has the potential to reduce antibiotic use, particularly when prevention of infectious disease reduces the incidence of conditions that would otherwise lead to antibiotic treatment. [8]

Vaccination has been available for many decades: first with vaccines to combat specific diseases such as foot-and-mouth disease and brucellosis, and subsequently through the development of increasingly sophisticated commercial vaccines by pharmaceutical companies.

We can say that veterinarians are an integral part of the decision-making chain in the use of vaccines on the farm: they suggest the type of vaccine, the vaccination plan and any diagnostic plan necessary to choose the correct application and verify vaccine effectiveness.

Once vaccination has reduced the pressure of specific infectious diseases, feed additives can further support animal resilience, gut integrity and immune response. The combination of vaccination, nutrition, biosecurity and appropriate veterinary management is therefore more consistent with an integrated disease-prevention strategy than the use of any individual intervention alone. [2,8]

5. Feed Additives and the Role of the Veterinarian 

On the other side, when we talk about feed additives (both zootechnical and nutritional), the choice of use, equally essential and equally routine, does not yet see (in our opinion) the Freelance Veterinarian as a decision-making party, because the choice is left in the hands of other farm stakeholders (farm owners, farm production managers, nutritionists and formulators).

This choice affects many other management aspects of farming: for example, the integration of a selenium-based additive into the diet can influence immune function, while the choice of an organic acid may contribute to control of certain microbial challenges. Selenium is an essential nutrient involved in antioxidant systems and innate and adaptive immune responses in poultry and pigs. [9]

Speaking of feed additives, especially if ATA, the veterinarian must own the various categories of nutritional and zootechnical additives: methods of use, mode of action, scientific data of efficacy, application and practical results on the farm, diagnostic tools to decide their application and verify their clinical and zootechnical efficacy.

Doing so, the veterinarian will take a proactive role and intervene in the management of the farm also in this sector.

6. Feed Additives, Gut Health and Immunity 

Feed additives are often cornered "only" to intestinal health; actually:

a. The gastrointestinal mucosa represents a major surface of contact between "self" and "non-self", between the animal organism and the outside world. The gastrointestinal tract functions not only as a site for digestion and absorption but also as an important metabolic and immunological organ and as a barrier against potentially harmful luminal constituents. Maintaining intestinal epithelial integrity can therefore contribute to limiting bacterial translocation and other consequences of impaired barrier function. [10]

Therefore, feed additives that maintain intestinal integrity may help reduce the risk associated with contamination by microorganisms and/or their toxic metabolites, including mycotoxins, bacterial toxins and lipopolysaccharide (LPS), at local and potentially systemic levels. [10]

b. The gut-associated lymphoid tissue (GALT) represents a major component of the body's immune system and is estimated in several reviews to contain approximately 70% of total immune system cells. [11] The action of nutritional interventions on the gut therefore has potential implications for both innate and adaptive immune protection, including responses associated with vaccination.

Therefore, feed additives can be considered one potential tool to support the well-being and resilience of the animal organism as a whole. However, their effects are dependent on the additive, dose, animal species, health status, diet, management system and environmental conditions. [2,3]

7. Scientific Evidence Supporting ATA 

The scientific literature dedicated to the effectiveness of zootechnical additives as alternatives to antibiotics is vast and has developed steadily over the last 20 years.

In 2016, an FAO publication dedicated to probiotics reviewed the scientific knowledge concerning probiotics in livestock production, including their mechanisms of action, applications, efficacy, safety and potential role as alternatives to antibiotic growth promoters. [12]

This publication contributed to a growing scientific literature examining the efficacy and practical application of these categories of livestock additives.

We find scientific evidence regarding probiotics, prebiotics, postbiotics, organic acids, phytogenics, peptides, bacteriophages and other bioactive feed additives. However, the strength and consistency of the evidence varies substantially between products and production systems. [2,3,12]

Worldwide, the main interest remains the possibility that zootechnical additives can replace or reduce dependence on growth promoters (AGPs), but there is growing scientific evidence of the effectiveness of these zootechnical additives for:

a. Stabilizing the anatomical and physiological integrity of the intestinal wall against stresses such as poor-quality raw materials, heat stress, mycotoxins and bacterial challenges. [10]

b. Supporting a beneficial intestinal microbiota and, as an indirect effect, helping to maintain control of pathogenic bacteria such as Salmonella, Escherichia coli and Clostridium perfringens. [2,3]

c. Supporting innate immune responses. [10]

d. Supporting immune responses associated with vaccination. Recent research, particularly in poultry, has investigated the effects of probiotics and other nutritional interventions on gut barrier function and immune-related responses. [13]

There is also a growing scientific literature on the effectiveness of nutritional additives such as amino acids and vitamins. Nutritional deficiencies can influence immune competence and susceptibility to infectious disease. Experimental research has, for example, demonstrated associations between amino-acid deficiency and the course of viral infection in poultry. [14]

Moreover, scientific evidence shows that some additives that would seem to play above all a nutritional role are able to play an important zootechnical role. Enzymes and selenium are examples of nutritional interventions that can influence nutrient utilisation, gut function and immune processes. [9,10]

This brief overview confirms that feed additives have the potential to contribute to animal health, farm performance and consequently the quality of livestock production. However, the evidence does not support treating all feed additives as equivalent; efficacy must be evaluated according to the individual product, formulation, target species, indication and production conditions. [2,3]

The impact of ATA depends not only on products or vaccination plans, but also on the management environment in which they are applied. Biosecurity and Precision Livestock Farming provide this operational framework. [15,16]

8. Biosecurity and Precision Livestock Farming 

Basic biosecurity, including the application of disinfection, pest-control and rodent-control plans, is a management element that can contribute to animal health, animal welfare and economic performance on the farm.

At the same time, livestock management has increased the use of practical biosecurity actions such as "shower-in/shower-out", staff dedicated to each phase of the farm, restrictions on personnel movement between production areas, the use of dedicated equipment and materials, and other measures designed to limit pathogen introduction and transmission.

Scientific reviews have identified an association between farm biosecurity and antimicrobial use, with improved biosecurity representing a potential means of reducing disease pressure and therefore the need for antimicrobial treatment. [15]

Today, these practices, along with the use of the ATA tools described above, can form part of an integrated approach to Precision Livestock Farming (PLF).

To PLF, we can also associate the application of diagnostic systems for infectious diseases and for the evaluation of the quality of the raw materials used in the feed, the quarantine of replacement animals (cattle and pigs), up to the continuous training of all breeding personnel.

Precision Livestock Farming technologies are increasingly being developed to monitor animal health and welfare parameters continuously or automatically, with the potential to detect health problems at an earlier stage and support more informed farm management. [16]

If used through modern IT and AI tools, PLF can facilitate its application on farms, becoming a "road-map" to achieve animal welfare and livestock production quality. Nevertheless, the scientific literature also emphasizes that PLF technologies should be implemented alongside appropriate management practices and that their welfare benefits depend on how the technology is used. [16]

9. Conclusion: ATA as an Integrated Strategy 

Taken together, vaccination, feed additives, biosecurity, diagnostics and Precision Livestock Farming form an integrated approach to reduce unnecessary antibiotic use, improve animal health and welfare, and support the quality and sustainability of livestock production.

The scientific evidence supports the concept that no single alternative to antibiotics should be viewed as a universal replacement. Instead, the most promising strategy is to combine preventive vaccination, appropriate nutrition, validated feed additives, strong biosecurity, diagnostics, veterinary oversight and data-driven farm management. [1,2,8,15,16]

ATA should therefore be understood as part of a broader animal-health strategy: the objective is not simply to remove antibiotics, but to reduce the conditions that make antibiotics necessary while preserving animal health, welfare and productivity.

This integrated approach is particularly relevant in the context of antimicrobial resistance, where responsible antibiotic stewardship must be accompanied by effective disease prevention and improved livestock-management systems.

References

1. Tang KL, Caffrey NP, Nóbrega DB, Cork SC, Ronksley PE, Barkema HW, et al. Restricting the use of antibiotics in food-producing animals and its associations with antibiotic resistance in food-producing animals and human beings: a systematic review and meta-analysis. Lancet Planet Health. 2017;1(8).

2. Abd El-Hack ME, El-Saadony MT, Salem HM, El-Tahan AM, Soliman SM, Youssef GB, et al. Alternatives to antibiotics for maximizing growth performance and feed efficiency in poultry: a review. Anim Health Res Rev. 2022;23(1):1-27.

3. Zhang Q, et al. Current advances in antimicrobial feed additives for terrestrial livestock: a systematic review. [Journal details to be verified against the final indexed record]. 2026.

4. Adedokun SA, Olojede OC. Optimizing gastrointestinal integrity in poultry: the role of nutrients and feed additives. Front Vet Sci. 2019;5:348. doi:10.3389/fvets.2018.00348.

5. European Parliament, Council of the European Union. Regulation (EC) No 1831/2003 on additives for use in animal nutrition. Off J Eur Union. 2003. Antibiotics other than coccidiostats and histomonostats could be marketed and used as feed additives only until 31 December 2005.

6. Ministry of Agriculture and Rural Affairs of the People's Republic of China. Announcement No. 194: withdrawal of certain medicated feed additives and adjustment of related management policies. Beijing: MARA; 2019.

7. Akinyemi F, et al. Antimicrobial usage in broiler chicken production in the United States, 2013-2021. Front Vet Sci. 2023. doi:[verify DOI in final manuscript].

8. Lawes J, et al. Impact of vaccination on antibiotic usage: a systematic review and meta-analysis. Clin Microbiol Infect. 2019.

9. Surai PF, Kochish II, Fisinin VI, Kidd MT. The role of selenium and selenoproteins in immune responses of poultry and pigs. Animals (Basel). 2019;9(12):987. doi:[verify exact bibliographic record].

10. Adedokun SA, Olojede OC. Optimizing gastrointestinal integrity in poultry: the role of nutrients and feed additives. Front Vet Sci. 2019;5:348. doi:10.3389/fvets.2018.00348.

11. Mowat AM, Agace WW. Regional specialization within the intestinal immune system. Nat Rev Immunol. 2014;14:667-685.

12. Bajagai YS, Klieve AV, Dart PJ, Bryden WL. Probiotics in animal nutrition: production, impact and regulation. FAO Animal Production and Health Paper No. 179. Rome: Food and Agriculture Organization of the United Nations; 2016.

13. Dietary probiotics modulate gut barrier and immune-related gene expression and histomorphology in broiler chickens under non- and pathogen-challenged conditions: a meta-analysis. Animals (Basel). 2023;13(12):1970. doi:10.3390/ani13121970.

14. Wiśniewski J, Larski Z, Wolszczak J. Influence of methionine and lysine deficiency in diets of chickens on HI antibody level and the course of Newcastle virus infection. Pol Arch Weter. 1972;15(1):31-40.

15. Can improved farm biosecurity reduce the need for antimicrobials in food animals? A scoping review. [Full bibliographic details to be verified in final reference database]. 2023.

16. Schillings J, Bennett R, Rose DC. Exploring the potential of Precision Livestock Farming technologies to help address farm animal welfare. Front Anim Sci. 2021;2:639678. doi:[verify final DOI].

Author

Dr. Paolo Doncecchi, DVM

Chief Technology Officer

Innova Biotechnology Sp. z o.o.

Warsaw, Poland

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