Abstract: The global issue of antibiotic resistance has prompted the ruminant farming industry to accelerate the search for alternative solutions to antibiotics. This paper reviewed the research progress of alternative additives such as probiotics,enzyme preparations,plant extracts,acidifiers,and bacteriophages in ruminants,and analyzed their effects on rumen fermentation,growth performance,immune regulation,and livestock product quality. The rational use of these additives can regulate the rumen microbiota,improve feed utilization,and enhance animal disease resistance. Among them,plant extracts have been reported extensively for improving milk and meat quality,and probiotics have some evidence supporting their role in alleviating weaning stress and reducing diarrhea. However,current research still faces challenges such as unclear mechanisms of action,instability of activity in the rumen environment,non-standardized dosages,and high costs. This paper suggested that future research could utilize multi-omics technology and real-time monitoring methods to explore precision nutrition strategies that move from single substitution to synergistic enhancement,providing a reference for green ruminant farming.

Key words: antibiotic substitution, ruminant animals, probiotics plant extract, rumen fermentation, green farming