The iron-zinc interrelationship in the chick as influenced by Eimeria acervulina infection

Two 14-day growth trials were performed to assess the effects of Eimeria acervulina infection (duodenal coccidiosis) on the Fe-Zn interrelationship in growing chicks. In the first assay, two levels of Fe (0 and 2000 mg/kg) were added to diets that contained either 0 or 52 mg supplemental Zn (from ZnCO3) per kilogram to establish whether excess Fe would affect Zn status of healthy and coccidial-infected chicks. In the second trial, either 0 or 2000 mg Zn/kg was added to diets containing 0 or 500 mg Fe/kg to determine whether Zn could modify Fe utilization. Based on chick performance as well as plasma Zn concentration, excess dietary Fe did not antagonize Zn in either healthy or E. acervulina-infected chicks. Coccidial infection, however, increased liver Fe and decreased intestinal Fe and hemoglobin concentration. Excess dietary Zn reduced performance and Fe content of tissues in both healthy and infected chicks. Coccidial infection ameliorated the adverse effects of excess Zn on performance and tissue Zn concentration and consequently enhanced Fe status of birds fed 2000 mg Zn/kg. These data suggest that the Fe-Zn interaction is a one-directional phenomenon in the chick, i.e., excess Zn reduces Fe utilization but excess Fe does not antagonize Zn.