ABSTRACT
An experiment was conducted using 360 one day old sexed male broiler breeder COBB chicks to investigate the effect of dietary Se source [inorganic-organic] supplementation in broiler diets with or without addition of probiotics in drinking water on productive performance and immune status of broiler chicken. The experiment was extended for 6 weeks. Inorganic Se source [sodium selenite] was supplemented in the basal diets of two groups, one of them drank water with 1ml/L probiotic and the second group drank water without probiotic. Organic Se source [OSY-E] was supplemented in the basal diets of another two groups one of them drank water with 1ml/L probiotic and the second group drank water without probiotic. Se sources were supplemented at the same dose [0.2 mg Se/ kg diet]. Body weight development, body weight gain, feed intake and FCR were calculated weekly. Serum GOT, GPT, uric acid and creatinine were determined. Lymphoid organs weight [bursa, spleen, thymus] were recorded and tissue of bursa was used for histopathological examination. Best body weight gain was achieved by groups received inorganic Se source in their diet. Probiotic in drinking water failed to improve body weight gain over that obtained from Se supplementation without probiotic. Feed intake from either inorganic or organic Se soure was lower than the control group. The entire treated group showed improving in FCR at different degree. Over all results of HI test, skin response test and lymphoid organs weight showed that Se supplementation in both source was improved the immune status of birds while the highest immune response achieved in birds received inorganic Se supplementation in their diet. It can be concluded that dietary Se supplementation in broilers diets succeed to improve both the productive performance and immune status of the birds, whereas the over all findings indicated that inorganic Se source superior over organic Se source