Abstract: Plant polysaccharides,a class of natural bioactive components extracted from plants,have garnered significant attention due to their distinctive physicochemical properties and diverse biological functions.Predominantly distributed in plant cell walls and mucilage layers,these compounds are recognized for their safety,high efficacy,low residue accumulation,and absence of drug resistance,demonstrating substantial potential in ruminant production systems.This article systematically examines the biological functions of plant polysaccharides,including antiviral activity,immunomodulatory effects,antioxidant capacity,gut microbiota regulation,and antitumor (anticancer) properties.Furthermore,it reviews recent advancements in their application to ruminant production,with particular emphasis on their demonstrated efficacy and mechanistic roles in enhancing growth performance,immune competence,gastrointestinal health,and product quality/safety.Regarding growth performance,dietary supplementation with plant polysaccharides has been shown to significantly increase daily weight gain,feed intake,and feed conversion ratio in ruminants,thereby improving production efficiency.In immune system modulation,these compounds promote immune organ development,stimulate immunoglobulin synthesis,and enhance anti-inflammatory cytokine secretion,collectively strengthening immunological defenses.For gastrointestinal health optimization,plant polysaccharides improve intestinal barrier integrity,modulate microbial community composition,and enhance cellular immune responses within the gastrointestinal tract,effectively reducing digestive disorder incidence.In terms of production performance,the addition of plant polysaccharides improve the physicochemical characteristics of meat products,enhances nutritional composition,and elevates the meat quality of ruminants. In the future,the research is needed on the biological functions and mechanisms of action of plant polysaccharides,providing useful references for the development and utilization of new feed additives,and laying the foundation for further research and application of plant polysaccharides in ruminant production.

Key words: plant polysaccharides; biological activity; ruminant; production performance; immune