EFFECT OF LEVAMISOLE ON HUMORAL IMMUNE RESPONSE TO NEWCASTLE DISEASE VACCINE IN INFECTIOUS BURSAL DISEASE VACCINATED BROILERS
EFFECT OF LEVAMISOLE ON HUMORAL IMMUNE RESPONSE TO NEWCASTLE DISEASE VACCINE IN INFECTIOUS BURSAL DISEASE VACCINATED BROILERS
No Thumbnail Available
Date
2009-02
Authors
JIBRIL, Adamu
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Foreign infectious bursal disease (IBD) vaccines imported into Nigeria are usually live attenuated intermediate or intermediate plus IBD virus strains and often associated with immunosppression in vaccinated birds. The use of levamisole to potentiate humoral immune response to vaccination against Newcastle disease (ND) in Ross broilers vaccinated with an intermediate strain of IBD vaccine was evaluated. Levamisole at 2.5 and 5 mg/kg dose was injected into the crop of broilers every other day for one week at 16, 30 or 62 days of age when IBD and ND vaccines were administered at 16 and 30, 30 and 44 days of age or challenge with ND virus and not administered IBD or ND vaccines at 62 days of age respectively. Control birds were not injected with levamisole. Antibodies against ND and IBD viruses were determined weekly by hemagglutination inhibition (HI) and agar gel immunodifussion (AGID) tests respectively. Other parameters determined include, packed cell volume (PCV) and total protein levels at 62 days of age; body weight, organ to body weight ratios for the bursa, spleen and thymus which were also examined by histopathology at 69 days of age. All sera tested for precipitin antibodies, following IBD vaccination were negative. High, HI mean ND virus antibody titers above 3 log2 were detected by 14 days of age but were low or absent at 35 days of age irrespective of administration of levamisole, IBD and ND vaccines. High antibody titers were obtained with 5 mg/kg levamisole dose. Broilers administered 5 mg/kg levamisole and IBD vaccine at 16 days of age had the highest mean log2 antibody titers at 21 (1.74 ± 0.40), 35 (0.95 ± 0.62) and 49 (4.56 ± 0.66) days of age with statistical significant difference at 42 and 49 (P< 0.001) days of age. Flock immunity against ND was observed at 28 and 40 days post administration of La Sota and day-old ND vaccination respectively. Broilers challenged
with ND virus at 62 days of age were protected. Levamisole had no significant effect on body weight and total protein of broilers (P> 0.05). Broilers administered La Sota vaccine and levamisole had lower mean PCV than those not vaccinated with La Sota and the difference in PCV was statistically significant (P< 0.001). Stimulation of the bursa, spleen and thymus was observed with 5 mg/kg levamisole dose. In older broilers 2.5 mg/kg levamisole dose had a stronger immunopotentiative effect on the bursa and spleen. For effective management of immonosuppresive effect of intermediate or intermediate plus IBD vaccine, poultry farmers should administer 5 mg/kg levamisole in drinking water every other day for one week, following vaccination with IBD vaccine at two weeks. There is the need to investigate the mechanisms involved in the age related stimulation of the bursa and spleen as well as the decrease in PCV caused by levamisole. The antigenic relationship between the IBD vaccine virus of intermediate strain and the IBD field virus used in the experiment should be determined.
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL, AHMADU BELLO UNIVERSITY,
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF MASTER OF SCIENCE IN VETERINARY MEDICINE
DEPARTMENT OF VETERINARY SURGERY AND MEDICINE,
FACULTY OF VETERINARY MEDICINE,
AHMADU BELLO UNIVERSITY ,
ZARIA-NIGERIA
Keywords
EFFECT OF LEVAMISOLE,, HUMORAL IMMUNE RESPONSE,, NEWCASTLE DISEASE VACCINE,, INFECTIOUS BURSAL DISEASE VACCINATED BROILERS.