Thirty newborn calves were supplemented with α-tocopherol (vit. E) (n=10), zinc (Zn) (n=10) or nothing (control) (n=10) for 8 weeks. All calves were vaccinated against tetanus at week 5. Plasma Zn and α-tocopherol were significantly increased in the Zn and vit. E groups, respectively. Plasma IGF-I levels generally increased from birth to week 8, but were not affected by Zn or vit. E. Daily weight gain was highest in the Zn group, but this was not related to an increased IGF-I level. The vit. E group responded earlier than the Zn and control groups to the tetanus vaccination.