Poultry Production Without Antibiotic Growth Promoters in Feed
For over six decades, Antibiotic Growth Promoters (AGPs) have been widely used in animal production, especially in poultry and swine, due to their benefits in performance and feed conversion.
- Studies indicate that the removal of AGPs may lead to an average 3.5% loss in feed conversion efficiency in broiler chickens, although in some cases no adverse effects are observed (CARDINAL et al., 2019).
Nevertheless, from the perspective of antimicrobial resistance development, the use of antibiotics at doses far below the minimum inhibitory concentration for the molecule, administered over long periods, significantly beyond those recommended for therapy, is not advisable, especially when the sole justification is performance improvement.
Although there is no definitive scientific evidence that this practice causes antimicrobial resistance relevant to hospital settings, it has led some countries to ban AGPs, while others are considering similar measures.
MECHANISMS OF ACTION OF AGPs
Despite AGPs having been used for more than 60 years, their mechanisms of action have only been elucidated in the last two decades, presenting a challenge for the production system, suppliers, and researchers searching for effective replacements.
Four primary mechanisms have been proposed through which AGPs enhance animal performance; all related to the intestinal tract:
- Inhibition of subclinical infections;
- Reduction of growth-inhibiting metabolites;
- Decreased nutrient consumption by microorganisms;
- Improved nutrient absorption and utilization due to a thinner intestinal wall.
In 2007, Niewold proposed an anti-inflammatory mechanism, and in 2012, Cho and collaborators demonstrated both anti-inflammatory and antimicrobial effects of AGPs. Understanding these mechanisms is essential for the development of effective and safe alternatives.
EFFECT OF AGPs ON THE INTESTINE
To understand AGPs’ primary effect on the intestine, one must first define the concept of Gut Health. Over time, this concept has evolved with field experiences and technological advances that allow for a better understanding of the microbiota.
- According to Kogut (2019), Gut Health involves a stable microbiota, a well-functioning mucus barrier, an appropriate immune response, and proper digestion and nutrient absorption.
Grasping these elements is key to identifying alternatives to AGPs, which can be grouped as follows:
- Probiotics: Live microorganisms that, in adequate amounts, benefit host health. They act by modulating the microbiota, maintaining epithelial homeostasis, and modulating intestinal immune responses.
- Prebiotics and Postbiotics: Non-viable dietary components that confer health benefits by acting directly on the gut microbiota (prebiotics) or the intestinal wall, regulating homeostasis and immune response (postbiotics).
- Symbiotic: A synergistic combination of probiotics and prebiotics.
- Phytogenics or Plant Extracts: Bioactive compounds from plants with antimicrobial, antioxidant, antiinflammatory, and intestinal wall regulating properties.
- Organic Acids: Mono- or carboxylic acids with direct antibacterial action and epithelial homeostasis support.
- Enzymes: Proteins that aid in nutrient breakdown, improving digestibility and absorption. They may indirectly modulate the microbiota and reduce excessive immune responses.
These alternatives provide viable options to enhance animal performance and promote gut health, thus playing a key role in replacing AGPs.
Figure 1. Clarifies the relationship between various technologies available as AGP replacements and the desirable outcomes of their use.
CHALLENGES AND OPPORTUNITIES RELATED TO GUT HEALTH
Defining the desired effects for each phase of the animal’s life and production conditions requires identifying the key challenges and opportunities related to gut health.
- Unlike AGPs, where a single active principle can be used throughout the bird’s life without the need for combinations, the alternative approach requires attention to specific challenges and the development of tailored programs.
- Neglecting this aspect can lead to ineffective or overly expensive programs without the expected economic return.
Therefore, it becomes clear that a feed-based alternative program to AGPs must be adapted to the specific challenges of each production phase and system.
Achieving the desired outcomes in each case requires combining two or more groups of alternative products. This tailored approach ensures effective and suitable results for each animal production context.
- A personalized strategy and careful combination of alternative products will be essential for sustainably promoting gut health and animal performance.
ROLE OF BIOSECURITY
Biosecurity plays a fundamental role in the effectiveness of AGP replacement programs in poultry production. It encompasses a set of preventive measures and strategies designed to minimize the introduction and spread of pathogens in poultry facilities.
- These measures are vital for ensuring animal health and welfare, especially in production systems that do not rely on routine antibiotic use.
- A key concept in poultry biosecurity is the control of access and movement of people, animals, and equipment on farms.
- Hygiene measures, such as designated clothing and footwear and vehicle disinfection, reduce the risk of cross-contamination.
- Another important element is maintaining a clean and appropriate environment within poultry facilities.
- Regular cleaning and disinfection of barns, equipment, and drinkers help reduce the presence of pathogenic microorganisms. Vector and pest control, including rodents and insects, is also essential to prevent disease transmission.
- Additionally, epidemiological surveillance and sanitary control measures are crucial aspects of biosecurity.
- Regular health monitoring, laboratory testing, and taking quick actions in response to disease detection are vital practices to prevent outbreaks and minimize their impact on poultry production.
- Biosecurity also involves the proper management of waste.
- The treatment and disposal of manure and dead birds are essential to prevent environmental contamination and the spread of pathogens.
- Ultimately, biosecurity is a key component of successful AGP replacement strategies.
- It ensures a healthy environment for birds, minimizes disease spread, and contributes to the sustainability of poultry production.
CONCLUSION
A strong commitment to biosecurity, combined with the judicious use of alternative products, can lead to a more responsible and efficient poultry industry, without compromising animal health or final product quality.
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