One hundred and ten 1-day-old broiler chickens were obtained from commercial breeder farm and kept under strict hygienic measures and were proved to be salmonella free. The birds were divided into 5 equal groups. The first group was kept as negative control. The second group was infected with (1×10⁸) Salmonella entertidis intra crop at 8^th day of age. The third group was given Sodium butyrate 0.98 mg/mL orally in drinking water from the first day till the end of experiment at 40^th day of age. The fourth group was treated with Sodium butyrate from the 1st day as in the 3^rd group and infected with Salmonella enteritidis at 8^th day of age. The fifth group was infected with inoculum containing (1×10⁸) Salmonella entertidis intra crop at 8^th days of age and treated Sodium butyrate 0.98 mg/mL in drinking water for 5 successive days after appearance of signs. Blood and serum samples were collected from each group at 14, 21 and 28 days of age for estimation of macrophages phagocytosis, malondialdehyde (MDA), Superoxide dismutase (SOD), total protein, albumin, globulin and Nitric Oxide (NO). Live body weight and feed intake were recorded for each repetition on
days 7, 14, 28 and 35. Reisolation of inoculated organism from the muscle, liver, and two ceci of experimentally infected chicks was carried out and confirmed by PCR. Tissue specimens from intestine were collected for histopathological examination. The results showed significant increase in total protein and globulin level in groups 2, 3 and 4. MDA showed significant decrease in group 2 and 4 in the first week, on the other hand MDA showed significant decrease in group 2 and 5 in the second week, but decrease in group 2 only in the third week. SOD showed significant decrease in group 2 in the first week, but in the second week, there were decrease in groups 2, 4 and 5. While SOD showed significant increase in groups 3, 4 and 5 in the third week. NO showed significant increase in groups 2 and 3 in the first week but in the second week there was significant increase in NO level in groups 2, 3 and 4 but in the third week the results revealed significant increase in groups 3 and 4 only. Macrophage showed significant decrease in groups 2 and 5. Phagocytic activity showed significant decrease in group 2 and significant increase in group 3. Body weight showed significant
increase in group 3 during the second and the third week of experiment, but in the fourth and fifth week there was significant decrease in group 2 and increase in group 3. Histopathological examination revealed that Group 3 (sodium butyrate) showed high absorptive surface from tall and thick intestinal villi and hyper activation of intestinal crypts and proliferation of villous enterocytes. The results indicated that sodium butyrate can be used as antioxidant so improve the growth performance in chickens under stress and this may be attributed to enhancing the immune response and reduce tissue damage. It was concluded that sodium butyrate can be used in control and prevention of salmonella infection in chickens