Mr. Johnson's Advance Hamster & Gerbil Food. It is a mono-component food which prevents selective feeding. This advice is a guide only. Iron: (E1) 161mg/kg, Manganese : (E5) 89mg/kg, Zinc Oxide : (E6) 69mg/kg, Copper : (E4) 20 mg/kg, Iodine: (E2) 0.8mg/kg, Selenium : (E8) 0.44mg/kg.