Evaluation of the Effects of Clove Essential Oil on Antibody, Haematological and Serum Biochemistry of Cockerels Challenged with Newcastle Disease Virus

Newcastle Disease (ND) is an important disease of poultry worldwide. It is a devastating disease that may cause up to 100% mortality in susceptible chickens. The aim of this study was to investigate the effects of oral administration of clove essential oil on blood biochemical and hematological parameters and on antibody responses of chickens to ND challenge. A total of 120 white leghorn chicks were obtained at days old. They were randomly allocated into four groups of 30 chicks each. Groups I, II and III chicks were treated with 330 Pass Per Million (PPM) of clove essential oil through drinking water while group IV chicks were not treated. At 6 weeks of age, chicks in groups I, II, III and IV were inoculated intramuscularly in the breast muscle with 0.2 ml of NDV Kudu 113 containing 10^8.46 embryo infective dose 50% end point per ml. On day 24 post challenge, the results of the mean total white blood cell counts were 1.50 ± 0.27, 3.00 ± 0.91, 1.88 ± 0.23 and 1.00 ± 0.00 for groups A, B, C and D respectively. The mean haemagglutination inhibition titres of chicks in group B were significantly (P ≤ 0.05) higher than that of groups D but not significantly (P ≥ 0.05) different from those of groups A and C chicks. Clove essential oil had significantly high enhancement effects on antibody responses but no significant effects on serum creatinine and uric acid concentration, serum enzymes (Alkaline Phosphatase-ALP, Alanine Aminotransferase-ALT and Aspartate Transaminase-AST), serum proteins (total protein, albumins and globulin levels), serum calcium and phosphorus concentrations, total red blood cell, packed cell volume and differential leucocytes counts.