Iron status of the chick as affected by Eimeria acervulina infection and by variable iron ingestion

Several experiments were conducted with crossbred chicks to investigate the effect of duodenal coccidiosis caused by Eimeria acervulina infection on iron status of chicks fed iron levels ranging from deficient to excess. Coccidiosis depressed weight gain and efficiency of feed utilization at all dietary levels of iron. Excess supplemental iron (500-1500 mg/kg) did not affect performance of uninfected chicks, but 1500 mg/kg iron exacerbated the coccidiosis-induced growth depression. In the presence of coccidiosis, 1000 and 1500 mg/kg iron significantly increased liver iron concentrations over that found in uninfected chicks fed the same levels of iron. Dietary iron increased intestinal iron content, but the increase was partially ameliorated by the coccidial infection. Plasma iron and total iron-binding capacity (TIBC) were decreased by acute coccidiosis (6 days postinoculation); however, by day 14 the coccidial infection was without effect on plasma iron, while TIBC tended to be elevated. Coccidiosis increased the chick's dietary iron requirement, but only because of decreased feed intake. Performance and hematological parameters were maximized approximately 0.9 mg iron per day in both control and infected chicks.