Broiler chickens could benefit from organically-complexed copper, iron, mangenese and zinc

Trace minerals are essential for broiler growth but supplemental inorganic trace minerals usually result in a high level of mineral excretion. Organically-complexed Cu, Fe, Mn and Zn may be alternative supplements in broiler diets due to a low rate of excretion. However, the requirements of these organically-complexed trace minerals for broilers are not known. Therefore, the current experiment was conducted to examine the effect of three levels of Cu (2,4, 8 mg/kg), Fe (20, 40, 80 mg/kg), Mn (20, 40, 80 mg/kg) and Zn (20, 40, 80 mg/kg) fed as proteinates (Organic I, 2, 3) on broiler performance and tissue trace mineral contents in comparison to a negative control (low-mineral basal diet) and a positive control (supplemented with sulphates). Both inorganic and organic minerals improved (P<0.05) broiler growth. The diets organically supplemented with 4 mg Cu, 40 mg Fe, 40 mg Mn and 40 mg Zn per kg diet (Organic 2) achieved (P<0.05) a superior FCR and lower mineral excretion than the inorganic control (P<0.05). The Cu, Mn and Zn contents in the tibia increased with the level of supplementation but there was no significant difference in plasma Cu, Fe, Mn and Zn contents among treatments. So organically-complexed Cu, Fe, Mn and Zn appeared to meet broiler requirements at lower levels than inorganic supplements and did not compromise broiler growth.