This work was designed to study the effects of fish oil supplementation and selenium-vitamin E (Se- vit. E) injection of Egyptian ewes and their Finnish Landrace Crossbred during the late stage of pregnancy on lambs response. Neonatal behaviors and growth performance of lambs including birth weight and average daily gain were recorded, while immune status of lambs was determined. Fifty-one pregnant ewes [native breeds (Ossimi and Rahmani, n=30) and their crosses with exotic Finnish Landrace breed (n= 21)] were selected and allocated to 3 experimental groups (n= 17 animals per group). The first group was fed with fish oil  supplemented diet for 6 weeks prior to lambing (40 gm Sardine oil /ewe/day); while the second group was injected by 2 successive doses of  Se- vit. E solution (5ml of 2mg sodium selinate and 100mg vitamin E) at 20 and 10 days before lambing. The third group was kept as a control. Lamb birth weight, neonatal behaviors, body temperature over the first 3d of life, average daily weight gain and mortality rates of lambs from birth until weaning were recorded. Blood samples were collected from each lamb, first sample was collected pre-suckling and the second one was at 24 h after birth for determination of phagocytic activity, white blood cell counts and serum total protein, including albumin and globulin. Lambs born to ewes of control group weighed less at birth and have an increased latencies to stand, reach the udder and suck successfully, and with a lower pre-suckling body temperature compared with those born to ewes supplemented with fish oil or others injected by selenium-vitamin E. These differences were more particularly observed in lambs born to native ewes than those born to crossbred ewes. Hematological analysis showed significantly higher white blood cell counts and phagocytic activity in lambs born to supplemented ewes than those born to control ones. No significant differences were demonstrated in pre-suckling concentrations of total serum protein, albumin and globulin between lambs born to treated ewes and those born to untreated ones. However, at 24h after birth, lambs born to supplemented ewes exhibited significantly higher concentrations of total protein and globulin than those born to control ewes. Moreover, lambs from supplemented ewes had significantly higher body weight gain with a minimal mortality rates from birth until weaning than those born to untreated ewes, specifically in ewes injected with selenium and vitamin E. We conclude that supplementing pregnant ewes with fish oil or selenium-vitamin E increases lamb birth weight, decreases the latency to stand and suckle and improves pre-suckling body temperature and immunocompetence of neonatal lambs with better lamb performance and survival.