Blood biochemistry responses of chickens experimentally infected with a Velogenic Newcastle Disease Virus (Kudu 113)

Abstract

This study investigated the blood biochemistry responses of cockerels  experimentally infected with a velogenic Newcastle disease virus (NDV) strain,  KUDU 113. One hundred Isa white cockerels were used for the study. The cockerels were obtained at day-old and randomly divided into groups A- vaccinated and  infected, B - unvaccinated and infected and C- unvaccinated and uninfected  (control) consisting of 30, 30 and 40 birds respectively. Group A was vaccinated against NDV with La Sota vaccine at three weeks of age while Groups B and C were not vaccinated. After six weeks, each bird in groups A and B were inoculated  intramuscularly (im) with the velogenic NDV while the control group was not  inoculated. Blood samples were randomly collected through the jugular vein from five birds in each group, allowed to clot at room temperature, centrifuged and serum  harvested. Blood biochemistry determinations were carried out on days 0, 3, 6, 9, 12, 15 and 21 post-inoculation (pi). Parameters determined included serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities, total serum proteins, albumin, globulin, total bilirubin, blood glucose level, total  cholesterol, total calcium, blood urea nitrogen and uric acid. Data generated were analyzed using ANOVA and Student’s t-test. Results showed decreased (p<0.05) total protein, albumin, globulin and total calcium levels and increased (p<0.05) plasma glucose and total cholesterol levels in groups A and B when compared with the unvaccinated uninfected control. Hypoproteinemia, hypoalbuminemia and hypocalcemia together with increased globulin, blood glucose and total cholesterol levels may be early signs of velogenic NDV infection in chickens. The absence of any negative effects on total proteins and calcium concentration in vaccinated infected when compared to the unvaccinated infected birds underscores the importance of vaccination not only in prevention of mortality due to velogenic NDV but also reduction of pathologic effects on vaccinated infected birds.

Key words: Chickens, Isa white, Velogenic NDV, KUDU 113, Blood biochemistry.