RESUMO
Eighty multiparous lactating Holstein cows (635 ± 33 kg) were used to study the effect of feeding Saccharomyces cerevisiae and/or Aspergillus oryzae on lactational performance for 14 weeks. Cows were assigned in a completely randomized experimental design, with repeated measures into four treatments, and were fed a basal diet of concentrates and forage at a ratio of 592:408, respectively. The treatments were: (1) the basal diet with no additive (Control treatment); (2) the basal diet supplemented with 3.5 g of live S. cerevisiae/cow daily (SC treatment); (3) the basal diet supplemented with 3.5 g A. oryzae fermentation extract/cow daily (AO treatment); and (4) the basal diet supplemented with 3.5 g of live S. cerevisiae + 3.5 g A. oryzae fermentation extract/cow daily (AOSC treatment). The AO and AOSC treatments increased (p < .05) feed intake and daily milk production, with a low milk fat content for the AO treatment. Feeding SC treatment decreased (p = .002) serum glucose concentration, while the AOSC treatment increased serum glutamate-oxaloacetate transaminase concentration. It is concluded that S. cerevisiae supplementation did not enhance milk production; however, A. oryzae fermentation extract improved feed intake and milk production.