Effect of dietary garlic on immune response of broiler chicks to live Newcastle Disease vaccine.

This study was designed to determine the effect of garlic powder on humoral immune response of broilers against NDV (Newcastle Disease Virus) vaccine. Two hundred and forty, two-day-old, Ross chicks were randomly assigned into 4 groups of 60 birds each. Chicks in groups 1 and 2 were given control mash diet during the experiment (6 week), but those in groups 3 and 4 were fed on control diet supplemented with 1 and 3% garlic powder, respectively. All groups except number 1 were vaccinated by eye-drop with B1 strain (Pestikal, Croatia) at 9 and 18 days of age. Ten blood samples were taken from each group on days 0, 14, 24 and 34 after first vaccination. The serum antibody level against NDV was measured by both HI and ELISA tests. The EDTA-mixed blood samples were examined for total and differential leukocyte count. The results showed that antibody titers in vaccinated chicks were significantly more than in non-vaccinated chicks (p < 0.05), but not influenced by the diet (p > 0.05). A significant increase of total leukocyte and percentage of lymphocytes was observed in vaccinated chicks 14 days after vaccination, but there were no difference (p > 0.05) among vaccinated groups. It is concluded that inclusion of garlic powder to the diet of broilers don't have any beneficial effect on humoral immune response to live NDV vaccine.