RESUMO
The aim of this study was to investigate changes in expression levels of immune factors of peripheral blood mononuclear cells (PBMC) after oral supplementation of live yeast Saccharomyces cerevisiae to healthy Japanese Black (JB) calves. This study examined JB calves (N=28): 14 calves (SC Group) received 10 g/calf/day of Saccharomyces cerevisiae (SC) (Acti-Saf Sc 47), and the other calves did not receive supplement (Control Group). Blood samples were collected 9 times during experimental period (1, 2, 3, 4, 5, 6, 7, 8 and 9 months of age), and analyzed for cytokines and chemokines mRNA expression of PBMC using Real-time PCR. The level of beta Hydroxybutanoic acid (BHB) in the SC Group was significantly high at 7 and 8 months of age compared to that in the Control Group. Lymphocyte counts in the SC Group were significantly higher at 2 and 5 to 6 months of age compared to the Control Group. Significant differences were found for IL-12p40 level at 4, 7 and 9 months of age, and for IFN-γ level at 6, 7 and 8 months of age. The level of CXCR3 was significantly higher at 6 to 7 months of age by dietary SC supplementation. These results indicated that SC supplementation improved the cellular immune responses of JB calves.