The aim of this study was to evaluate the effect of dietary selenium supplementation (organic or inorganic) to the diet of late pregnant and lactating ewes on their productive and growth performance of their suckling lambs. Sixty late pregnant ewes (30 Farafra and 30 Saidi) had age ranged from 2 - 4 years and of average weight 45.0 ± 1.4 kg for Farafra and 43.12 for Saidi ewes were used in this study. All ewes were chosen fertile and healthy, with single born lamb with every breeding and free of internal and external parasites. Ewes of every breed were divided into three similar groups (10 ewes each). All ewes fed in groups according to NRC (1985). The control group fed the basal ration + 100 gm starch powder without any supplement, while the tested group (T1) fed 0.3 mg Sodium Selinate/kg diet and the tested group (T2) fed the basal ration + 0.3 mg Selenium yeast /kg diet. Results indicated that milk yield was the highest with T2 (590 and 564 kg) followed by T1 (583 and 551 kg) and lastly the control (545 and 502 kg) for both breeds (Farafra and Saidi, respectively), the differences were significant only between Se-yeast ration (T2) and the control one. The improvement of milk yield was better with Saidi (9.76 and 12.35%) compared with Farafra ewes (6.97 and 8.26%) for the two tested treatments (T1 and T2, respectively). Milk contents of fat and total solid were slightly increased with the two tested rations in comparison with the control one, while protein content was significantly higher only with T2. compared with control ration. Body weight at birth and weaning was improved with the tested rations. The significance of improvement was associated only with T2 for weaning weight of Farafra ewes, in comparison with control ration. The daily gain and total gain measured for suckling lambs had the same trends of birth weaning weight among the dietary treatments. Also, the obtained data indicated that weaning weight, daily body gain (DBG) and total body gain (TBG) were significantly higher with Farafra than those of Saidi lambs with both treatments (T1 and T2). Hematocrit (Ht%), Sodium and Potassium levels did not significantly effected by the tested experimental rations. The highest value of total protein in Saidi ewes recorded with T2 (6.23 g/d) followed by T1 (6.06 g/d) and lastly the control (5.78g/d) but the differences were not significant. Also, similar trend respecting total protein was observed among the dietary treatment with Farafra ewes, but the difference was significant only between T2 and control ration. Total antioxidant was significantly higher in T1 and T2 compared with control group, while the highest value was recorded with T2 in both breeds.