Abstract

The increasing global demand for sustainable livestock production necessitates alternatives to antibiotic growth promoters, with postbiotics emerging as a viable solution due to their stability, safety and bioactive properties. This review synthesizes research on postbiotics-non-viable microbial components or metabolites, such as those derived from Saccharomyces Cerevisiae Fermentation Products (SCFP), Aspergillus oryzae and Lactobacillus spp. and their effects on ruminant health and productivity. Findings indicate that postbiotics enhance rumen fermentation by stabilizing pH, increasing volatile fatty acid production and modulating microbial populations, particularly fibrolytic bacteria such as Ruminococcaceae and Lachnospiraceae. Immunomodulatory benefits include reduced inflammatory markers (e.g., IL-6, TNF-α) and improved gut barrier function, achieved through the upregulation of tight junction proteins. Species- and dose-dependent responses are evident, with dairy cows showing improved nutrient digestibility and immunity, while beef cattle exhibit variable outcomes in rumen fermentation. Postbiotics also demonstrate antimicrobial effects, reducing pathogens like Salmonella and Staphylococcus aureus. Despite promising results, efficacy depends on the formulation, dosage and the animal’s physiological stage. This review highlights postbiotics as a strategic tool to enhance ruminant performance while aligning with One Health principles, though further research is needed to optimize their application across production systems.

Keywords:Postbiotics; Ruminant nutrition; Saccharomyces cerevisiae; Rumen fermentation; Immunomodulation; Antimicrobial resistance; Gut health; Feed additives; Sustainable agriculture