ROLE OF PROBIOTICS IN POULTRY PRODUCTION: A SYSTEMATIC LITERATURE REVIEW

Abstract

The world poultry market is experiencing a drastic shift to sustainable production models whereby there are more limitations on production growth promoters of antibiotics (AGPs) and the risk of antimicrobial resistance is increasingly becoming noticeable. Probiotics has emerged as one of the emerging functional feed additives which is capable of enhancing the growth performance, gut health and immune competence of chickens. The existing data on the effectiveness, mechanisms, and the strategies of probiotic supplementation use in the rearing of poultry, were organized in this systematic literature review and meta-analysis. In qualitative synthesis, 119 articles were used and in quantitative meta-analysis, 87 articles were used as PRISMA 2020 identified 1,246 records in PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar. As it was demonstrated in the pools, the body weight gain (g = 0.94) and the ratio of feed consumed to the body weight (g = -0.88) of the probiotic-supplemented birds was statistically better than the controls. The most performing formulations were the multi-strain formulation formulations and Lactobacillus based formulations. Probiotics supplementation had a tremendous effect in stimulating Newcastle Disease Virus antibody titer and expression of the antiinflammatory cytokine genes (IL-10), inhibiting pro inflammatory conditions (IFN-g, TNF-a). The histomorphometric analysis demonstrated that height of the villus, ratio between the villus and the crypt, integrity of the intestinal barrier and the microbial diversity with lesser pathogen colonization was also increased. To conclude, the available evidence shows that probiotics are scientifically proven, long-term substitutes of AGPs, which lead to the more productive poultry systems, immune regulation, and better gastrointestinal health. The findings substantiate the fact that strain-specific probiotic intervention should be incorporated in precision feeding programs to boost sustainable production of poultry in the post-antibiotic period.