In the present study, birds fed on inorganic and organic Fe supplemented diets
had better performance and nutrient retention than birds fed on control (without
any Fe supplementation) diet. In agreement with our findings, Vahl and Klooster
(1987) had reported maximum growth in birds receiving 20 to 60 mg/kg
supplemental Fe when compared with birds fed on diets without any
supplemental Fe (containing 100 mg/kg of Fe contributed by dietary components).
Moreover, in another study, chicks fed on a semi-purified casein-soya protein
based diet (containing 46·5 mg Fe/kg) had 60% less BW gain than those fed on
the same diet supplemented with 50 mg Fe/kg (Aoyagi and Baker, 1995).
Iron deficiency is known to influence the intestinal mucosa functionality by
decreasing the villus surface area (Saiz et al., 1993), which might partly explain
the reduced nutrient retention as noticed in birds fed on control diet without
any Fe supplementation.