Experimental Salmonella Gallinarum infection in point of lay pullets: Correlation of hematology and oxidative stress with egg production

Abstract

Salmonella Gallinarum is a bacterial pathogen linked with drop in egg production in poultry. In this study, hematological and oxidative stress (OS) parameters were evaluated and correlated with egg production in point of lay (POL) pullets infected with S. Gallinarum. Fifty 18-week-old POL pullets were randomly assigned to two groups of 25 POL pullets per group. The infected POL pullets were orally inoculated with S. Gallinarum (109S. Gallinarum colony forming units/mL), while the uninfected pullets were the controls. Hematological and OS parameters were determined using standard methods. There were significant (P < 0.05) loss of body weight and drop in egg production in the infected POL pullets when compared to the controls. Acute hemolytic anemia of the macrocytic hypochromic type was observed. The total white blood cell (TWBC), absolute heterophil, lymphocyte, eosinophil and monocyte counts, mean serum malondialdehyde (MDA) level, glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities were significantly (P < 0.05) higher in the infected POL pullets when compared to the controls. There was a strong association between heterophilia and drop in egg production. An association was also established between significantly elevated GPx, SOD and CAT, which have antioxidant properties, and clinical outcome, including subsequent weight gain and rise in egg production, suggesting that antioxidants may be useful in the treatment of fowl typhoid. It was concluded that S. Gallinarum infection of POL pullets caused significant hematological changes, induced OS, and stimulated the body’s antioxidant defense mechanism to elaborate GPx, SOD and CAT.