Antimicrobial Resistance (AMR) has become a “silent pandemic,” with the potential to cause 10 million deaths annually if not addressed, according to the World Health Organization (WHO). The use of antibiotics in food systems is recognized as a significant driver of AMR. In the poultry sector, both broilers and layers, this includes the overuse of antibiotics critical to human health. It’s imperative to control and limit the unnecessary use of antibiotics for growth promotion or mass disease prevention. Additionally, poultry farm waste is a pathway for the emergence and spread of AMR. Resistant Salmonella and Campylobacter strains linked to poultry products pose considerable risks to human health.
As the global momentum to curb antibiotic misuse in animal production grows, several countries have started implementing measures. In 2022, 47 nations, including India, committed to the Muscat Manifesto targets to reduce antimicrobial use in agri-food systems.
However, the poultry sector remains vital for livelihoods, nutrition, and the economy, and its growth must be sustainable. A promising approach to reducing antibiotic misuse lies in focusing on preventive measures such as vaccination, biosecurity, housing systems, breeds, feed, and nutritional or non-antibiotic alternatives. This article explores evidence-based alternatives to antibiotics, including probiotics, phage therapy, and phytogenics, which address AMR while supporting sustainable poultry farming.
Probiotics: Harnessing Beneficial Bacteria
Probiotics—live microorganisms that offer health benefits to the host—are emerging as a promising alternative to antibiotics in poultry farming. These beneficial bacteria colonize the gut, enhancing nutrient absorption, boosting immunity, and outcompeting pathogenic bacteria.
A good probiotic should not be pathogenic or toxic, should have a positive impact on the host (e.g., competitive exclusion of pathogens), and must be able to survive and remain viable in the gut environment, as well as under feed processing and storage conditions. Probiotics can be single-strain or multi-strain, with multi-strain formulations often offering more benefits due to their synergistic effects.
Research has shown that probiotics can improve growth performance, reduce mortality rates, and enhance feed conversion efficiency in poultry. Probiotics also improve gut health and reduce the incidence of necrotic enteritis, a common bacterial disease in poultry.
Phage Therapy: Precision Targeting of Pathogens
Phage therapy, utilizing bacteriophages (viruses that specifically target bacteria), is an innovative method for combating bacterial infections with precision. It is increasingly seen as a valuable alternative to traditional antibiotics, particularly in addressing multidrug-resistant pathogens.
Phages target specific bacterial receptors, injecting their genetic material, replicating inside the host, and eventually causing the bacterial cell to burst, releasing new phages. This highly specific action ensures that only harmful bacteria are affected, leaving beneficial microbes unharmed.
Phage therapy has shown promise in controlling bacterial infections such as Salmonella and Campylobacter in poultry. For example, phage cocktails reduced Salmonella colonization in broiler chickens by 99%. Phage therapy can also be used preventively, incorporated into feed or water to manage bacterial populations before infection occurs. Advances in genetic engineering have allowed for the modification of phages to enhance their effectiveness against even the most resilient bacterial strains.
Phytogenics: Harnessing the Power of Plants
Phytogenics, plant-derived compounds, present another promising alternative to antibiotics. These natural substances, including essential oils, flavonoids, and tannins, possess antimicrobial, anti-inflammatory, and antioxidant properties.
Key Phytogenic Compounds:
- Essential Oils: Compounds like thymol, carvacrol, and cinnamaldehyde have shown antimicrobial effects, particularly against pathogenic bacteria, while improving gut health.
- Tannins: Found in plants such as chestnuts and acacia, tannins reduce bacterial adhesion to the gut lining and help modulate immune responses.
- Flavonoids: These antioxidants protect against oxidative stress and enhance nutrient absorption.
Key Benefits of Phytogenics in Livestock:
- Enhanced Digestive Health: Phytogenics promote better gastrointestinal function by stimulating digestive enzyme production, leading to improved nutrient absorption.
- Natural Antimicrobial Properties: Many phytogenic compounds help control harmful bacteria in the digestive system, reducing the likelihood of intestinal disorders.
- Improved Growth and Performance: By enhancing nutrient utilization and supporting immune function, phytogenics can boost growth rates, feed conversion efficiency, and overall livestock performance.
- Reduced Environmental Footprint: Phytogenics provide a sustainable alternative to synthetic additives like antibiotics, which contribute to antibiotic resistance and environmental pollution. Additionally, better nutrient absorption reduces nutrient excretion, further minimizing environmental impact.
- Enhanced Meat Quality: Phytogenic compounds can positively influence meat quality, improving attributes such as tenderness, flavor, and shelf-life through their antioxidant effects.
Phytogenics are an effective and sustainable solution for promoting animal health, improving growth performance, and enhancing feed efficiency in broilers. Their use aligns with growing consumer demand for natural and environmentally-friendly farming practices.
The Path Forward: Integrating Alternatives
No single alternative can entirely replace antibiotics in poultry farming. A holistic approach, integrating probiotics, phage therapy, phytogenics, and other innovations, is necessary. This strategy, often referred to as “One Health,” recognizes the interconnectedness of animal, human, and environmental health.
Conclusion
The shift away from antibiotics in poultry farming is not only essential but also an opportunity for innovation. Probiotics, phage therapy, and phytogenics offer promising solutions to reduce reliance on antibiotics while improving animal health and productivity. By embracing these alternatives, the poultry industry can contribute to a healthier, more sustainable future for all.
by Gautam Shukla, Rajasthan University of Veterinary and Animal Science (RAJUVAS)
