Increase in resistance to acute experimental coli-septicaemia in chicks given high levels of ferrous sulphate in the diet.

The resistance of chicks to coli-septicaemia following injection of approximately 10(8) cells of Escherichia coli O78 was found to be appreciably increased in terms of mortality by the supplementation of their diet with 360 mg/kg or more of iron in the form of commercial hydrated ferrous sulphate. This was related to an increase in the plasma iron levels. The results suggest that increased resistance to infection could be partly achieved by correcting the hypoferraemia which has previously been shown to be produced in chickens by injections of E coli endotoxin lipopolysaccharide (LPS). The results also showed that haematological disturbances in survivors of coli-septicaemia can persist for up to at least 30 days after infection.