The research was conducted on broiler Broiler breeder hens (Ross 308) to determine the effect of flax oil, palm oil, and vitamin C on physiological performance and immune status. The mothers were divided into 5 treatments (20 chickens and 4 roosters/treatment): the first treatment (control), the second treatment (2% flax oil), the third treatment (2% flax oil + vitamin C 300 mg/kg feed), the fourth treatment (2% palm oil), and the fifth treatment (2% palm oil + vitamin C 300 mg/kg feed). Mothers were vaccinated against Newcastle disease at the ages of 46 and 50 weeks, and blood samples were collected during the research. The results showed that the addition of flax oil significantly reduced (P≥0.05) the level of cholesterol, triglycerides, and adding vitamin C significantly increased both the concentration of total protein and globulin and the proportion of globulin:albumin and decreased the level of cholesterol and triglycerides significantly compared to control. The addition of palm oil led to a significant increase in the concentration of both globulin and the proportion of globulin:albumin, HDL – C and ALT significantly, reduce the concentration of triglycerides and the ratio of HDL – C: LDL – C significantly. With the addition of vitamin C, the concentration of glucose and HDL – C: LDL – C decreased significantly, and the concentration of HDL-C and ALT was significantly increased. The antibodies titer against Newcastle disease did not differ significantly for all treatments except for the flax oil treatment, which outperformed the treatments by 52 weeks of age, and the heterophils and heterophil/lymphocyte (H/L) ratio decreased significantly, and the proportion of mononuclear cells to flax oil treatment increased significantly compared to control.