One hundred and twenty Golden Montazah laying hens (Egyptian local developed strain) aged 24 weeks were divided in two groups each group contains four treatments with two different supplemental sources of zinc, inorganic zinc as zinc sulphate (ZnSo4 7H2O) and organic zinc as zinc methionine to get concentration levels 0.0, 50, 100 and 150 mg supplemental zinc/kg diet to investigate the effect of different dietary levels and sources of zinc and their interaction on the zinc concentration of egg, the productive performance, some egg quality and some blood parameters of laying hens were also estimated. The experimental period lasted for 12 weeks in three subsequent interval periods (four weeks each). Results indicated that increasing zinc levels from 0.0 up to 150 mg/kg either as inorganic or organic significantly increased egg zinc concentration without any adverse effect on egg production. The highest concentration of egg zinc was observed for layers fed diet supplemented with 150 mg zinc/ kg diet as an organic Zn (Zn methionine). Supplementing laying hens' diet with zinc as zinc methionine significantly increased egg production. In that, 100mg supplemental zinc as Zn methionine gave the best feed conversion and egg mass. Also, organic zinc supplementation significantly increased plasma zinc, total protein, albumen, and globulin and improved A/G ratio. Albumen index and Haugh unit significantly affected by increasing zinc levels.
In conclusion supplemented laying hens diet with 150 mg zinc as zinc methionine / kg diet gave zinc enriched egg which could supply 19.45 % of daily requirements of zinc for children from 1-8 years and additionally gave advancement in productive performance for laying hens.