Haematological and some biochemical changes in experimental fowl typhoid infection in broiler chickens

A study was conducted to evaluate the effect of Salmonella Gallinarum (9, 12) infection on broiler chicks infected through oral and intraperitoneal routes. One hundred and ten broiler chicks (1 week of age) were divided into three groups: group CR (30 chicks) were kept uninfected and served as control group, group OR (40 chicks) were inoculated orally with Salmonella Gallinarum (109 organisms/ml) and group IP (40 chicks) were infected intraperitoneally with Salmonella Gallinarum (109 organisms/ml). Three birds from each group (including those that die) were sacrificed at 3, 5, 7, 14, 21, 28, 35 and 42 days post infection (DPI). Clinical signs were noticed as early as 12 h after intraperitoneal infection and on 3 DPI after oral infection. Higher mortality of 47.50% was observed in intraperitoneally infected chicks as compared to 22.50% in orally infected birds. Decreased body weight and reduced feed intake were observed in chicks in both the infected groups; however, the effects were more marked in chicks infected intraperitoneally. Mean values of haemoglobin, packed cell volume and total erythrocyte count were significantly lower (P < 0.05) in both orally infected as well as intraperitoneally infected chicks. Leucocytosis observed in both the infected groups was due to increase in the number of heterophils and lymphocytes. Significant decrease (P < 0.05) in serum total protein and serum albumin was observed in intraperitoneally infected birds only. However, the values of aspartate transaminase and alanine transaminase were increased significantly (P < 0.05) in both the orally infected and intraperitoneally infected birds.