A total of 320 fertile eggs, were divided randomly into 4 treatments with four replicates and 20 eggs per each replicate. Treatments including: T1; control; without injection, T2; injected with 0.1ml saline solution; sham control, T3, injected with0.1 ml either containing 0.75 ppm inorganic or Nano – iron particles 75 ppm Fe-Nano inorganic, T4, injected with 75 ppm Fe inorganic  On the 7th day of incubation, 0.1 ml solution was In ovo injected into the egg .Body weight and body weight gain were measured at biweekly intervals, at 42d of age, three hens per replicate were weighted, sacrificed for slaughtering weights of carcass, internal organs(heart, liver, and lymphoid organs i.e. (spleen, thymus and Bursa) were recorded. Blood samples were collected at slaughtering bird at 42d of age. There were significant increase in body weight and body weight gain in treatments injected with75 ppm Fe-Nano inorganic and 75 ppm Fe inorganic compared with control. There were no significantly differences among all experimental groups in dressed carcass, gizzard, and heart, liver. Abdominal fat decreased in groups injectedwith75 ppm both iron forms. Compared with the control group. No variation was observed in the weight of bursa and spleen, however thymus weight was significantly higher in both Fe inorganic and Fe nano inorganic injected groups than un-injected control group. High density lipoprotein concentration and cholesterol were significantly decreased by different treatment as compared with the control group. These results suggest that, 75 ppm Fe inorganic or75 ppm Fe-Nano injection at the 7th im
proved at the 7th day of incubation improved embryonic growth and development as well as decreasing post hatched chick's plasma cholesterol.