The effects of lower levels of organically complexed zinc, copper and manganese in broiler diets on performance, mineral concentration of tibia and mineral excretion.

Summary The effects of replacing inorganic with lower levels of organic trace minerals of Zn, Cu and Mn on growth performance, mineral excretion and mineral concentration in tibia were investigated in broilers. One-day-old Ross-308 broiler chicks were used. Chicks were divided into 4 different groups as 1 control and 3 experimental groups consisted of 50 chicks. All groups were also divided into 5 replicates containing 10 chicks. Starter (0-21 d) and fi nisher (21-42 d) broiler diets which not included Zn, Cu and Mn were used. Specially prepared mineral premix (containing at 40 mg Zn, 80 mg Cu and 60 mg Mn levels of inorganic minerals in each kg as sulphate form) added to control diet in the level of recommended by NRC. Mineral content of the control diet was prepared using standard inorganic mineral premix that refl ects the normal supplementary levels and source of trace minerals for commercial broiler feed recommended by National Research Council. In the experimental diets, mineral premix was also prepared as inorganic forms except of Zn, Cu and Mn. Organically complexed Zn, Cu, and Mn were separately added into basal diet at 1/3, 2/3 and 3/3 proportions as BioplexTM instead of inorganic forms of those mineral recommended levels by NRC. Experiment lasted 42 days. Results showed that organically complexed trace minerals can be used at a much lower concentration than the current recommended as inorganic minerals, without a negative impact on performance, while also decreasing the excess mineral excretion. Further studies are needed to determine the proper level of organic trace minerals by taking tibia mineral levels into consideration.