امیر جوادی فر

The aim of the present study was to evaluate the effect of zinc oxide on production performance, egg quality and antioxidant status of layer hens. This experiment was performed with 96 Bovens strain layer hens at peak production (28-35 weeks) in a completely randomized design with 3 treatments with 4 replicates and 8 hens each for 3 periods of 28 days. The treatments included control group (without zinc oxide nanoparticles) and two levels of 100 and 200 mg zinc oxide nanoparticles (ZnONPs) /kg of diet. Experimental diets were provided to laying hens for 8 weeks. Zinc oxide nanoparticles increased the egg mass (32-35 wk), and decreased feed intake (28-31wk) compared to control (P<0.05). The ZnONPs did not affect the egg production and egg weight. The haugh unit (31 and 35 wks) and quality traits of egg shell including eggshell stability (31 and 35 wks), and relative weight of eggshell and specific gravity (35wk) increased with increasing ZnONPs supplementation in diet (P<0.05). The concentration of total protein, HDL, and antibody against Newcastle disease were not affected by ZnONPs supplementation level. The use of ZnONPs supplementation reduced the concentration of cholesterol, triglyceride, LDL, concentration of MDA in blood and yolk, and the activity of the enzyme ALT (P<0.05). The ZnONPs supplementation increased the antibody titer against the influenza and increased zinc concentration in the blood. The results of this research showed that supplementation of 200 mg of ZnONPs per kg of layer diet may improve the growth performance indices, hough unit and egg shell quality, and decrease the blood lipids and improve immune response in layer hens at peak production.

In order to investigate the effects of different levels of iron nano-oxide(INO) on performance, egg quality parameters and the antioxidant status of laying hens, 96 Bovens layer hens at the production peak(28 weeks) were used. The experiment done for 8 weeks in a completely randomized design with 3 treatments, 4 replicates and 8 birds in each replicate. Hens were fed with experimental diets containing 0, 50 and 100 mg iron nanooxide/kg of diet. The performance indices included egg production, egg weight, egg mass, feed intake and feed conversion ratio were daily recorded. The qualitative parameters included yolk color index, egg shape, yolk height index, Haugh unit, Eggshell thickness, eggshell strength, Specific gravity and relative weight of albumen, yolk and eggshell were determined at the end of each period(28 days). At the end of experiment, two birds per replicate were bleed and the blood biochemical parameters were studied.The results were revealed that the iron nano-oxide had no effect on performance indices. Total protein and enzyme activity of alanine aminotransferase were not affected by dietary INO.Dietary supplementation of INO decreased the serum concentration of cholesterol, triglyceride, and LDL, and increased serum concentration of HDL, iron, zinc. The antibody titer against Newcastle disease were increased with increasing the levels of dietary INO. The yolk and serum concentration of MDA was increased by the addition of iron nanoparticles. Therefore, the addition of iron oxide supplementation can improve performance indices, some qualitative characteristics of egg and immune response and decrease serum lipid in laying hens.