The cattle with adequate alpha-tocopherol (Vit E) and marginally deficient selenium (Se) status manifested significantly lower anti-Haemophilus somnus antibody titer than the cattle supplemented with Se in the later stage of an 8-week trial. However, in the early stage no difference was observed in magnitude of anti-H. somnus antibody development between them. These results suggested that Se may contribute to anti-H. somnus antibody production, and that Vit E can make up for Se deficiency to a certain degree.