The effect of varying dietary zinc levels on growth and antibody-mediated response in two strains of mice.

The objectives of the present study were to determine the zinc requirement of two strains of young growing female mice. The strains tested were outbred Swiss mice and inbred A/J mice. In addition to using growth as a criteria of zinc adequacy, the response to immunization with sheep red blood cells (SRBC) was measured in each strain at various dietary zinc levels. The dietary levels of zinc fed in a biotin-fortified egg white diet were: 0.7, 3.3, 5.9, 8.2, 11.0 and 31.4 mg/kg. It was found during a 3-week experimental period that the outbred Swiss mice attained maximum growth and normal antibody-mediated response at a zinc level in the diet of 5.9 mg/kg. The inbred A/J mice in a 2-week experimental period were also able to attain maximum growth and normal antibody-mediated response at 5.9 mg Zn/kg. It is concluded that there were no differences in the zinc requirement for growth of the two strains of mice used and also that the zinc requirement for immunological competency as measured by the Jerne plaque assay using SRBC antigen were similar. The results indicate that the mouse has a lower dietary requirement for zinc than the rat.