Effects of Organic and Inorganic Forms of Manganese, Zinc, Copper, and Chromium on Bioavailability of These Minerals and Calcium in Late-Phase Laying Hens.

In the present study, the effects of dietary supplementation of organic and inorganic Mn, Zn, Cu, and Cr mixtures using two different levels (80, 60, 5, and 0.15 mg/kg and 40, 30, 2.5, and 0.07 mg/kg, respectively) on the bioavailability of these trace minerals and Ca in late-phase laying hens were evaluated. Three hundred and sixty laying hens (Barred Rock) at 50 weeks of age were used, and the duration of study was 16 weeks. Each of the four dietary regimes was randomly assigned to six replicates, which included 15 hens each. Organic trace minerals were provided as methionine chelates; inorganic Mn, Zn, and Cr were provided as oxides; and Cu was provided as sulfate. The organic form significantly increased the concentrations of serum Mn, Zn, Cu, and Ca; egg Mn, Zn, Cu, and Cr; and eggshell Zn and Cr compared with the inorganic form. However, the form of trace minerals did not affect the concentrations of serum Cr and eggshell Mn, Cu, and Ca. High-level addition of trace minerals significantly increased serum Mn and Zn; egg Mn, Zn, Cu, and Cr; and eggshell Mn, Zn, and Cu concentrations compared with low-level addition but did not affect serum Cu, Cr, and Ca or eggshell Cr and Ca concentrations. While the organic form reduced the excretion of Mn, Zn, Cu, Cr, and Ca, the high-level supplement increased Mn, Zn, and Cu excretion. The addition level did not affect Cr and Ca excretion. These results demonstrate that dietary supplementation of an organic Mn, Zn, Cu, and Cr mixture increases the bioavailability of Mn, Zn, Cu, Cr, and Ca compared with inorganic sources and that a lower level of trace mineral supplementation results in lower mineral excretion, particularly in an organic form.