Investigation of Egg Enrichment Using Organic and inorganic Supplements of Selenium and Zinc in aged Laying Hens

This experiment was performed to investigate the effects of organic and inorganic sources of minerals zinc and selenium on yield, egg quality and selenium and zinc concentration in eggs in older laying hens. In this experiment, 210 Leghorn laying hens-line strains (w-36) at the age of 83 weeks were used based on a completely randomized design. Treatments included seven treatments with three replications and 10 chickens in each replication. Treatments included two inorganic sources of zinc and selenium including zinc oxide and sodium selenite and two organic sources of zinc methionine and selenomethionine and control treatment. Production yield, egg quality and selenium concentration on eggs were evaluated for six weeks. The results showed that organic and inorganic sources of zinc and selenium in the diet of laying hens did not have a significant effect on production performance and internal quality of eggs. Addition of zinc and selenium supplements from organic sources improved egg shell quality compared to the control group. Organic and inorganic sources of selenium and zinc increased selenium and zinc stores in eggs at 85 and 87 weeks (P <0.05) .There was no significant difference between organic and inorganic sources for egg enrichment with selenium and zinc. Increased selenium and zinc storage was observed up to 88 weeks old laying hens. Addition of zinc and selenium supplements from organic sources improved egg shell quality.