Еffectiveness of yeast probiotics in implementing the "No Antibiotics Ever" strategy in broiler farming

Abstract

NAE stands for "No Antibiotics Ever" and refers to a type of poultry diet and management prac-tice in which chickens are raised without the use of any antibiotics from hatch to harvest. This practice is part of a broader trend in the poultry industry to meet consumer demand for antibiotic-free meat and to address concerns about antibiotic resistance. Instead of antibiotics, NAE rely on enhanced biosecurity measures, vaccination programmes, and the use of probiotics, prebiotics, and other natural health-promoting additives to maintain bird health. The study on the effectiveness and safety of probiotic yeast strains was conducted on Ross 308 broiler chickens, divided into five groups. Each group received a specific diet, with or without probiotic supplementation. Blood, tissue, and droppings samples were collected for the analysis of biochemical, immunological, and productive indicators. The research demonstrates that with the complete absence of antibiotics during the growing period, the inclusion of probiotics in broiler diets contributed to an increase in the levels of short-chain fatty acids in the faeces, which play a crucial role in ensuring optimal digestion, immune response, pathogen protection, nutrient absorption, and high productivity levels. The application of Kluyveromyces marxianus, isolated, identified, and characterised in the Research and Development laboratory as a probiotic feed additive for broiler chickens, shows promising potential for improving productivity, enhancing gut microbiota balance, and supporting digestive function through increased short-chain fatty acid production.