Two experiments were respectively conducted with 200 one day-old Avian broiler chicks to estimate bioavailability of different iron sources and manganese sources for broiler chicks. factorial design was used in both experiments. Broiler chicks were allotted randomly to ten dietary treatments with four duplicates that included an unsupplemental corn-soybean basal diet (44mg/kg Mn or 94mg/kg Fe) or this basal diet supplemented with 60, 120 or 180mg/kg Mn either as MnSO4 H2O, manganese acetate or yeast mangane...