Effects of Supplementary Mineral Methionine Chelates (Zn, Cu, Mn) on the Performance and Eggshell Quality of Laying Hens

Preparation of chelatesCu methionine chelate : Eighty grams of D,Lmethionine and 66.94 g CuSO 4 ⋅5H 2 O were completely dissolved in 1 l and 500 ml of distilled water, respectively, at 65±5°C.These two solutions were mixed at a molar ratio of 2:1 for a reaction to occur to which 50% NaOH solution was gradually added to increase pH up to 7 for maximum precipitation.Precipitate was separated, dried in an oven at 50°C for 2 days and then made to powder which was subsequently tested to confirm approximately 16% Cu by analysis.The product was dissolved in distilled water and tested for chelation.Test with copper specific electrode (Model 720A, Orion Research Inc. 529 Main St., Boston, MA 02129 USA) showed app.25% of Cu was ionized and the remaining undissociated Cu (app.75%) was regarded as chelated (Kim et al., 1997).Zn and Mn methionine chelates : Eighty grams of D,L- Effects of Supplementary Mineral Methionine Chelates (Zn, Cu, Mn) on the Performance and Eggshell Quality of Laying Hens