الفهرس 
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Abstract
This study was conducted at the Faculty of Agriculture (Poultry Production Department), Alexandria University, during the period between April to June of 2020. The aim of this study was to evaluate the effect of different forms and levels of zinc oxide as zinc oxide bulk and nanoparticles as a feed additive on productive, reproductive performance and immunological response of Alexandria local chickens. A total of 165 birds (150 female and 15 male) Alexandria chicken strain of 32 weeks of age were used and randomly divided into five groups in each group 30 females and 3 males in three replicates, the experiment lasted for 12 weeks from 32 weeks of age to 44 weeks of age, five hatches were obtained from fertile eggs and one day old chicks were produced. The first group served as control group. Birds of the 2nd and 3rd groups were fed basal diet containing 40 and 80 mg zinc oxide (Bulk shape, ZnO) per kg diet and the 4th and 5th groups were fed basal diet containing 40 and 80 mg zinc oxide (Nano shape, ZnO-NPs) per kg diet, respectively. The productive performance of the flock was evaluated, egg production traits for females, estimation of egg components, calculation of fertilization and hatching rates, counting the number of hatched chicks, estimating hematological and some biochemical parameters, estimation of zinc level in some tissues, histological sections in the liver and kidneys tissue, and the economic efficiency of the experiment was studied. The most important results obtained from this study were summarized in the following points: • The addition of zinc oxide in the nano form at a concentration of 80 mg / kg diet increases insignificantly the egg production of each female during 90 days, egg mass per grams and egg production percentage compared to the control group.
• The results showed that the use of different forms and doses of zinc oxide in the Alexandrian chicken diets led to a non-significant improvement in the feed conversion ratio, but in general, the treatments were better than the control.
• The addition of 80 mg ZnO bulk and nanoparticles /kg diet caused a significant increase in the percentage of fertility, the increment ratios were 11.70 and 11.46% of control, respectively.
• With regard to hatchability percentage, the dose of 80 mg ZnO bulk and nanoparticles /kg diet led to a significant increase of 10.93 and 10.05% of control.
• There was a significant increase in the weight of day-old chicks with increasing doses of zinc oxide, this increase reached a maximum with the dose of 80 mg/kg of zinc oxide in the form of nanoparticles, which reached 103.68% of control.
• The use of different doses and forms of zinc oxide caused a positive effect but not significant on the composition of the egg in terms of total lipids concentration, but significant in terms of total protein concentration.
• The interaction between zinc oxide forms and doses and sex had a significant effect on erythrocytes profile, where the highest value of RBCs counts in male blood with the dose 80 mg/kg diet of ZnO bulk, while the highest value of it in females’ blood were with the control group (9.04).
• There is an effect of different forms and levels of zinc on Hb, HCT and MCH, where the dose of 40 mg/kg diet of zinc oxide in nano form recorded the highest value for both Hb and MCH, it was 113.34 and 115.92% respectively, while the highest value for HCT was recorded with the dose of 80 mg / kg diet of zinc oxide in the bulk form compared to the
control.
• The addition of zinc oxide in the nano form at a dose of 80 mg/kg diet caused a significant increase in the total protein and albumin levels by (22.93 and 41.89%), respectively, 11 compared to the control group, while globulin level was not affected by the different forms and levels of zinc.
• The interaction between the effect of sex and the different forms and levels of zinc led to a significant increase in both total protein and albumin, where the highest level was in the blood of females and males with the dose 80 mg/kg diet at increased rates (131.24, 150.31 and 113.88, 132.09%) of control for both total protein and albumin levels, respectively.
• The addition of zinc oxide at a dose of 80 mg/kg and 40 mg/kg of nano form led to a decrease in the levels of triglycerides and cholesterol with decreased rates (13.48 and 21.44%) compared to the control, respectively.
• LDL reached a maximum value with the control group (80.98%), while HDL was not affected by the different forms and levels of zinc oxide, sex or the interaction between them.
• Sex had an effect on the blood content of ALP, as it was higher in the blood of males than females, with an increase rate of 24.63% compared to the control group.
• Results indicated that both the different forms and levels of zinc oxide and sex had a significant effect on FSH and LH concentrations, the treatments were higher than the control in the level of FSH, but with regard to LH, the dose of 80 mg/kg diet of zinc oxide in the form of nanoparticles led to a significant increase in its level, which reached 109.32% of control.
• The level of zinc in the blood of birds was affected by the different forms and levels of zinc, sex and the interaction between them, as the dose of 80 mg/kg diet of zinc oxide in the form of nanoparticles recorded the highest concentration of zinc with an increase of
70.59% of the control.
• Progesterone hormone was not significantly affected by the use of zinc oxide in its different forms and levels, while testosterone was affected by the addition of zinc oxide compared to the control.
• The addition of different forms and levels of zinc had a significant effect on the blood content of immunoglobulins in general compared to the control.
• The dose of 40 mg/kg diet of zinc oxide in the bulk form led to a significant increase in the blood content of IgM at a rate of 24.97% compared to the control.
• Antibody titers against New Castle disease improved, but insignificantly, in the blood of males, females and chicks in this study.
• The use of different forms and levels of zinc oxide had a significant effect on antioxidants concentration, GPx, CAT, SOD, MDA and TAC, as the dose of 80 mg/kg diet of zinc oxide in the form of nanoparticles led to a significant decrease in the MDA content, which was 23.31% of control, and a significant increase equal to 40.36, 38.18 and 35.45% of control for CAT, SOD and TAC, respectively.
• There are no significant differences for the use of different forms and levels of zinc oxide on zinc content in eggs, meat, liver and kidneys tissue.
• The results of the economic efficiency showed a significant improvement in the efficiency characteristics as a result of using zinc oxide, and it reached a maximum when using the dose of 80 mg/kg diet of zinc oxide in the form of nanoparticles.