['After the recent outbreak of foot-and-mouth disease (FMD) in Korea, a vaccination policy has been applied to control the disease. In addition, several non-specific immune stimulators have been used without any scientific evidence that they would enhance the immune response after FMD vaccination and/or protect against FMD. Based on the current situation, the aim of this study was to evaluate the effect of the non-specific immune stimulator germanium biotite on FMD vaccination and immune responses in cattle. To achieve our goal, immune responses to FMD vaccination, such as levels of IgG and IgA, antibody duration, and virus-neutralizing titers were investigated after germanium biotite feeding. The PBMC typing and proliferative response after stimulation with mitogens, the cytokines expression level of PBMC, and the lysozyme activity in the serum were measured to evaluate the immune enhancing effects of germanium biotite following its administration.', "Following the first vaccination, high level of IgG (at 4\xa0weeks) and IgA (at 2 and 31\xa0weeks) titers in serum and saliva were observed in the germanium biotite-feeding group (p\u2009<\u20090.05). The germanium biotite group also showed high and longstanding inhibition percentage value in ELISA assay at 31\xa0weeks (p\u2009<\u20090.05). Generally, higher virus-neutralizing antibody titers were observed in the feeding group at 20 and 31\xa0weeks after vaccination. Following the feeding germanium biotite, the germanium biotite group showed increased subpopulation of CD4+ lymphocytes and MHC I+II+ cells in PBMCs at 23\xa0week, responding to stimulation of ConA. The levels of IFN-γ (at 3 and 8\xa0weeks), IL-1α (at 3, 11, and 23\xa0weeks), IL-1β (at 3, 8, and 11\xa0weeks), and IL-4 (at 8 and 11\xa0weeks) gene expression were also significantly increased in the feeding group (p\u2009<\u20090.01 and p\u2009<\u20090.05). Feeding with germanium biotite increased the lymphocytes' proliferative response to the stimulation of ConA and LPS at 23\xa0weeks and lysozyme activity at 9\xa0weeks after feeding."] Does supplementation of dietary germanium biotite enhance induction of the immune responses by foot-and-mouth disease vaccine in cattle?