ABSTRACT: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.

A total number of 90 APRI rabbits at 5 weeks of age were divided into nine treatments, 10 rabbits each, to investigate the effect of different dietary digestible energy (DE) and crude protein (CP) levels in a 3x3 factorial design on rabbits growth performance, carcass traits, blood plasma constituents and nutrients digestibility during the fattening period (5-13 weeks of age). Rabbits were fed different three levels of DE 2500, 2600, and 2700 kcal DE/kg diet each with 14, 16 and 18 % CP level. The results showed that the highest body weight, daily weight gain and growth performance were obtained with 2600 Kcal DE/Kg diet followed by those fed diet containing 2500 Kcal DE. Increasing dietary protein to 16% CP significantly increased live body weight, daily weight gain, growth performance and performance index and improved feed conversion ratio. There were no significant effect due to DE or protein levels on digestibility coefficient of DM, OM, EE and NFE, while fiber digestibility coefficient decreased with increasing DE. Crude protein digestibility coefficient increased by increasing protein level. There were no significant effect on plasma constituents due to energy levels except in case of triglycerides and cholesterol. CP levels affected significantly on total protein, albumin, globulin and creatinine. Increasing CP increased total edible parts, while no significant differences could be detected due to DE levels. Meat content of DM, CP and EE were increased by increasing DE and protein level. In conclusion the optimal protein and energy levels for APRI rabbits in the present study are 16% CP with 2500 kcal DE/kg diet to maximize the productive performance and economic efficiency.

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