摘要Background Nicotinamide riboside(NR)supplementation has been demonstrated efficacy in enhancing female reproductive outcomes,but its regulatory role in sow performance and gut microbiome remains undefined.This study systematically evaluated the impacts of dietary NR supplementation during late gestation and lactation on sow performance and gut microbiome remodeling.A total of 280 sows were randomized assigned to one of four groups:a control group fed basal diet or one of three groups receiving NR-supplemented diets(2,4,or 8 g/d;n=70/group).Sow reproductive performance,blood metabolic parameters,milk metabolome,and fecal 16S rRNA sequencing were measured.Results Maternal NR supplementation linearly shortened farrowing duration(P＜0.01)and tended to decrease the incidence of intrauterine growth restriction and the number of late gestation mummies(P＜0.1),while concur-rently increasing the within-litter uniformity(P=0.1).Litter weaning weight and average daily gain increased quad-ratically with NR dosage(P＜0.05).NR supplementation orchestrated plasma metabolite regulation(triglycerides and total cholesterol;P＜0.05),enhanced antioxidant biomarkers(T-AOC,GSH-Px,T-SOD;P＜0.05),and reduced inflammatory cytokines(TNF-α;P＜0.05)across gestation and lactation.Milk yield,colostrum/milk dry matter,crude protein,and crude fat were increased(P＜0.05),together with higher levels of NAD+metabolites(NAD+,NR,nicotinamide)and beneficial bioactive factors(milk polar lipids,3-aminosalicylic acid,fenugreekine;P＜0.05).Gut microbiota analyses at lactation day 14 revealed NR-enriched beneficial taxa(Bifidobacterium,Ruminococcus,Lachno-spiraceae,Subdoligranulum,Clostridium butyricum,Succiniclasticum)across sow-offspring dyads,which was associated with the activation of microbial NAD+enzymes(NadR/NAMPT;P＜0.05)and enhancement of systemic short-chain fatty acid flux,notably an increase in plasma butyrate acid(P＜0.05).Conclusion Maternal supplementation of NR during late gestation and lactation increases sow performance and promotes gut NAD+metabolic-associated microbiome remodeling.These findings propose maternal NR inter-vention as a novel strategy to enhance mammary lactogenesis and lactation metabolism in swine production,with potential applications for therapeutic strategies for lactation insufficiency.