Evaluation of the effects of experimental Salmonella gallinarum infection on the haematology and oxidative stress markers in young pullets

Abstract

The effects of Salmonella gallinarum infection on the haematology and oxidative stress (OS) in pullets were evaluated in this study. Fifty 7-week-old pullets were randomly assigned to two groups of 25 pullets per group. The infected pullets were inoculated orally with S.
gallinarum (10⁹ S. gallinarum colony forming units/mL), while uninfected pullets were the controls. Haematological and OS parameters were determined following standard protocols. There was a significant loss (p<0.05) of body weight. The packed cell volume (PCV), haemoglobin (Hb) concentration, red blood cell (RBC) count and mean corpuscular haemoglobin concentration (MCHC) were significantly lower (p<0.05). In contrast, the mean corpuscular volume (MCV) was significantly higher (p<0.05) in the infected pullets when
compared to the controls. The total white blood cell (TWBC), absolute heterophil, lymphocyte, eosinophil and monocyte counts, of the infected pullets, were significantly higher than that of the controls. Serum malondialdehyde (MDA) level, glutathione peroxidase (GPx) and catalase (CAT) activities of the infected pullets were significantly higher (p<0.05) when compared to the uninfected controls. Absolute heterophil count correlated strongly, positively and significantly with MDA. An association was established between significantly elevated GPx and CAT, which have  antioxidant properties, and survival/health improvement indices such as improved weight gain and self-recovery. It was concluded that S. gallinarum infection of pullets caused significant alterations in the haematology, induced OS, and stimulated the body’s antioxidant defence mechanism to elaborate GPx and CAT. This may suggest the use of antioxidants in the treatment of fowl typhoid.