Some plasma biochemical changes in layers experimentally infection with Pasteurella multocida

The present study was carried out to investigate some biochemical alterations in layers experimentally infected with Pasteurella multocida. A total of 20 eighteen-week old ISA Brown layers were used in the experiment. The birds were randomly assigned to two groups (infected and control) of 10 layers each. To establish infection, each bird in the infected group was challenged by intra nasal (0.1 ml) and intramuscular (0.4 ml) administration of P. multocida inoculum containing 4.5 × 108 CFU/ml. Meanwhile, birds in the control group were given clean drinking water and fed standard commercial layers mash ad libidum. All the experimental birds were monitored closely for clinical signs of fowl cholera. Blood samples were collected from both groups at day zero (Day 0), 2, 4, 7, 14, 21, 28, 35, 42, post-infection (pi) and used to assay some biochemical parameters. By day 5 post-inoculation (pi), all birds in the infected group manifested clinical signs typical of fowl cholera; weakness, ruffled feathers, sneezing, greenish-yellowish diarrhoea, decrease in feed and water consumption, weight loss, drop in egg production and mortality rate of (20%). However, there were significant increase in the plasma activities of aspartate amino transferase, alanine aminotransferase, alkaline phosphatase, and level of uric acid and significant hypoproteinaemia. The experimental P. multocida infection initiated hepatic, intestinal and renal dysfunctions. Key words:  Pasteurella multocida, cholera, ISA brown layers.