This study evaluated the effects of live yeast and yeast cell-wall mannan-oligosaccharide supplementation on
performance and nutrient digestibility during early lactation in cows fed a diet based on a mixture of corn silage and alfalfa hay as forage
sources. Eight multiparous Holstein dairy cows (average days in milk, 27±6) were used in a replicated 4×4 Latin square design. Diets
contained 45% forage and 55% concentrate on a dry matter (DM) basis and treatments were: i) basal diet without additive (Control), ii)
basal diet with 32 g/d of mannan-oligosaccharides (MOS), iii) basal diet with 1.2×1010 colony forming units per day (cfu/d) of live yeast
(Saccharomyces cerevisiae CNCM 1-1077; SC), and iv) basal diet with a mixture of MOS (32 g/d) and SC (1.2×1010 cfu/d; MOS+SC).
Treatments had no effect (p>0.05) on DM intake and yields of milk, 3.5% fat-(FCM) and energy-corrected milk (ECM), and on milk fat
percentage, body condition score and blood metabolites. Compared with the Control, only supplementation of SC resulted in
numerically higher yields of FCM (41.9 vs. 40.1 kg/d) and ECM (41.8 vs. 40.3 kg/d), and milk fat percentage (3.64 vs. 3.43%). While
the MOS diet had no effects on performance compared to the Control, the combination treatment MOS+SC increased milk protein
percentage (p