Probiotics in poultry farming: A review

Abstract

Probiotics and prebiotics are currently postulated as a potential replacement alternative to sub-therapeutic antibiotics as growth promoters. The advantage is that these agents do not leave residues in the egg or meat of the poultry, and do not cause risk of developing antibiotic resistance in human microbiota. The use of probiotic microorganisms, mainly lactic acid-producing bacteria in poultry feeding, contributes to maintaining the integrity and stability of the intestinal flora. This hampers the proliferation of harmful microorganisms, which helps to prevent the onset of disease and improves productive performance. Nevertheless, regarding their effect as growth promoters, results are contradictory, largely because of the variety of microorganisms and doses that can be administered, the type of poultry used, methods of administration, diet compositions, and environmental conditions in which bioassays are performed. Therefore, given the need to eliminate antibiotics as growth promoters, it is essential to continue researching and expanding our knowledge of these additives, by conducting bioassays to determine bacterial strains and the most suitable methods of administration in modern poultry lineages under intensive production. The objective of this review is to present an analysis of the conditions under which these substances work, and to explain why their effects are sometimes insignificant.