Colostrum quality is of paramount importance in the management of optimal ruminant growth and infectious disease prevention in early life. Live yeast supplementation effect during the last month of gestation was evaluated on ewes’ colostrum composition. Two groups of ewes (n=14 for each group) carrying twin lambs were constituted and twins were separated into groups (mothered or artificially-fed) 12h after birth. Nutrients, oligosaccharides (OS), IgG and lactoferrin concentrations were measured over 72h after lambing, and bacterial community was described in colostrum collected at parturition (T0). Immune passive transfer was evaluated through IgG measurement in lamb serum. In both groups, colostral nutrients, OS concentrations and IgG concentrations in colostrum and lamb serum decreased over time (p < 0.01) except for lactose, which slightly increased (p < 0.001) and lactoferrin which remained stable. Bacterial population was stable over time with high relative abundances of Aerococcaceae, Corynebacteriaceae, Moraxellaceae and Staphylococcaceae in T0-colostrum. No effect of supplementation was observed in nutrient and lactoferrin concentrations. In supplemented ewes, colostral IgG level was higher at T0 and a higher level of serum IgG was observed in lambs born from supplemented mothers and artificially-fed, while no effect of supplementation was observed in the mothered lambs. Using a metabolomic approach, we showed that supplementation affected OS composition with significantly higher levels of colostral Neu-5Gc compounds up to 5h after birth. No effect of supplementation was observed on bacterial composition. Our data suggest that live yeast supplementation offsets the negative impact of early separation and incomplete colostrum feeding in neonate lambs.