STRATEGIES FOR ANTIBIOTIC-FREE MANAGEMENT IN BROILERS

STRATEGIES FOR ANTIBIOTIC-FREE MANAGEMENT IN BROILERS

Introduction

As concerns over antibiotic resistance continue to grow, there's an increasing emphasis on antibiotic-free management strategies in the poultry industry, particularly in broiler production. In this era, where housing conditions, pathogen exposure, and dietary nutrients significantly impact gut health, adopting antibiotic-free management becomes imperative. This approach aims to enhance gut health by reducing stress, implementing precision nutrition, preventing exogenous infections, and refining breeding environments. This article provides an overeview of antibiotic-free management strategies, focusing on key aspects such as feed quality control, feed additive enzymes, prebiotics, probiotics, organic acids, and plant extracts. By examining these strategies, we aim to elucidate their efficacy and potential in promoting the health and performance of broilers while reducing reliance on antibiotics.

1.     Probiotics;

Probiotics are live microorganisms added to feed as a supplement, known for their ability to improve growth, feed efficiency, and intestinal health in poultry. They exert antibacterial effects on the intestinal microflora, promoting the growth of beneficial bacteria while inhibiting harmful pathogens. By enhancing the development of the intestinal immune system, probiotics aid in activating both innate and adaptive immune responses, contributing to overall health and disease resistance in poultry.

Specifically, probiotics play a crucial role in reducing the negative effects of coccidiosis, a common poultry disease, by minimising its spread and maintaining gut health. They stimulate the production of endogenous enzymes, decrease metabolic reactions, and promote the synthesis of vitamins and antimicrobial substances. Probiotics also produce bacteriocins, antimicrobial peptides that inhibit the production of toxins and the adhesion of pathogens, further enhancing gut health.

Moreover, probiotics influence gene expression patterns and the composition of the intestinal microbiota, leading to improved nutrient absorption and utilisation. They upregulate the expression of genes related to nutrient transport, such as sugar transporter genes, and enhance the diversity and abundance of beneficial bacteria in the gut. Overall, probiotics offer a natural and effective way to support poultry health, immunity, and performance, making them valuable alternatives to antibiotics in poultry farming.

2.     Plant Extracts;

Plant extracts, categorised into phenolics, alkaloids, sulphur-containing compounds, and terpenoids, offer potential as phytogenic feed additives in poultry nutrition. Among them, ginger and oregano are preferred due to their lower odour sensitivity compared to garlic and rosemary. Essential oils derived from plants serve as promising alternatives to growth promoter antibiotics, with demonstrated preventive and curative roles in conditions like necrotic enteritis in broilers. For instance, oregano essential oil supplementation has been associated with increased average daily gain in broiler chickens. 

Plant extracts, such as Guduchi (T. cordifolia), exhibit positive effects on poultry growth performance and immune function, serving as potent immunomodulators and antimicrobial agents. These extracts modulate immune responses, possess antibacterial and antioxidant properties, and influence digestive processes and enzyme activity, ultimately enhancing broiler performance and health. Additionally, specific plant compounds like grape seed proanthocyanidin, leonurine hydrochloride, genistein, epigallocatechin-3-gallate, and quercetin show promising effects in mitigating oxidative damage, improving intestinal health, and enhancing immune function in poultry.

3.     Feed additive enzymes (FAE)

Feed additive enzymes are indispensable tools in poultry nutrition, serving various crucial functions to enhance feed efficiency and promote overall health. Among these enzymes, Phytase stands out for its ability to modify villi and crypts morphology, resulting in improved average daily gain. Phytase offers valuable antibacterial properties, particularly effective against clostridium perfringens, providing essential treatment options for bacterial infections. Additionally, FAE effectively addresses the negative effects of coccidiosis on gut health and function. By facilitating the absorption of micronutrients and optimising growth performance, exogenous multi-enzyme complexes further contribute to the benefits of FAE in poultry diets. Incorporating FAE into feed formulations not only improves nutrient utilisation but also supports better growth and welfare outcomes for poultry, thus reinforcing their significance in modern poultry production practices.

Curcumin supplementation has been found to boost the expression of certain genes related to detoxification and increase the levels of glutathione, a potent antioxidant, in the intestines. This helps in enhancing the body's defence mechanisms against harmful substances. Similarly, yeast cell wall supplementation plays a role in improving intestinal health by regulating the glutathione pathway, enhancing nutrient absorption, and reducing the activity of proteolytic enzymes, which can damage the gut lining. These interventions offer promising alternatives to antibiotics by promoting gut health and bolstering the immune system, ultimately aiding in the prevention of bacterial infections.

4.     Feed quality control;

Feed quality control is paramount in poultry production, with particular attention given to combating mycotoxins, including aflatoxins, fumonisins, and zearalenone, which pose significant health risks to poultry. Prevention strategies, such as biological control using beneficial microorganisms, maintaining appropriate environmental factors, and ensuring favourable storage conditions, are essential in minimising mycotoxin contamination. 

Feed fermentation techniques, including solid-state fermentation (SSF) and submerged fermentation (SmF), play a crucial role in enhancing feed quality. Fighters produced in SmF, such as fungal strains, aid in breaking down anti-nutritive factors in feeds, leading to improved growth performance, gastrointestinal tract microflora, gut morphology, immune system function, and overall poultry welfare. By implementing these strategies, poultry producers can ensure high-quality feeds and mitigate the adverse effects of mycotoxins on poultry health and productivity.

5.     Organic Acids;

Organic acids, including short-chain fatty acids and medium-chain fatty acids, serve as alternatives to antibiotics by exerting antimicrobial activity, particularly outside the gut. Their specific antibacterial effects target pathogenic bacteria such as Escherichia coli, Salmonella, and Campylobacter, thereby promoting gut health in broilers. Incorporating organic acids into feed or drinking water at appropriate concentrations has been shown to enhance growth, feed conversion rate, and feed utilisation in broilers. For instance, butyric acid, derived from low-digestible feed proteins, acts as an energy source for intestinal epithelial cells, stimulating proliferation and differentiation and ultimately improving feed efficiency. 

Supplements like L-theanine and taurine have demonstrated benefits in enhancing growth performance, immunity, and antioxidant status in chickens. These natural additives, along with organic acids, can positively impact intestinal morphology and microbial composition, contributing to overall broiler health and performance while reducing reliance on antibiotics.

6.     Prebiotics;

Prebiotics are non-digestible compounds, such as short-chain polysaccharides and oligosaccharides, that stimulate the growth and activity of beneficial bacteria in the intestines of broilers. They are metabolised by gut microbes to produce short-chain fatty acids, which contribute to the overall health of broilers. Prebiotics have been shown to reduce harmful bacteria like Campylobacter in the gut and improve broiler performance by positively affecting gut health. By altering the composition of gut microbes, prebiotics promote a healthier gut environment, leading to enhanced broiler performance and reduced reliance on antibiotics.

Summary;

There’s no one single ideal solution for antibiotic resistance. Several measures and alternatives to antibiotics are to be used in conjunction to one another to achieve perfect gut health free of antibiotics.

REFERENCE

1. Zhu, Q., Sun, P., Zhang, B., Kong, L., Xiao, C., & Song, Z. (2021). Progress on Gut Health Maintenance and Antibiotic Alternatives in Broiler Chicken Production. Frontiers in Nutrition, 8, 692839. https://doi.org/10.3389/fnut.2021.692839