Immunomodulating Effect Of Aqueous Extracts Of Some Herbal Plants On Newcastle Disease Virus Vaccinated Broilers :- Ohaeri Chidiebere P

ABSTRACT xvi One hundred and five broilers were used to determine the immunomodulatory effect of aqueous extract of Ocimum gratissimum leaves, Azadirachta indica leaves and Tetrapleura tetraptera pods on broilers vaccinated against Newcastle disease virus and fed with the concentration of Img/ml and O.lmg/ml of each plant extract. Blood samples were collected for analysis of haematological parameters and NDV antibody titre. The antibody titre against Newcastle disease was significantly higher (P<0.05) in birds that received Img/ml and O.lmg/ml of Ocimum gratissimum than in birds exposed to other plant extracts on day 14 and day 28. Also the H.I titre of birds exposed to O.lmg/ml of Tetrapleura tetraptera was not significantly different from the control on day 7 and 14 post exposure, but suddenly started increasing on day 28 and became the highest on day 42. The mean values of Total white blood cell (TWBC), Packed Cell Volume (PCV) and Red Blood Cell (RBC) Count of broilers treated with O.lmg/ml of Ocimum gratissimum and Img/ml of Tetrapleura tetraptera were significantly (P<0.05) higher on day 14 than the rest of the groups. There was a significant (P<0.05) increase on the mean Red Blood Cell Count of broilers treated with O.lmg/ml of Ocimum gratissimum on day 42. It was found that Ocimum gratissimum gave the highest immune response on the experimental birds against Newcastle disease while Tetrapleura tetraptera had a slow onset of action and a longer duration of antibody titre. It was then recommended that Ocimum gratisssimum should be used as an adjuvant to boost immunity of broilers up to day 28 against Newcastle disease and also as a haematinic in boosting Red Blood Cell production.