Abstract

Echeonwu G. O. N*, Iroegbu C. U, Echeonwu B. C, Ngene A4, Nwosuh C. I, Joannis T. M and Ndako J.

Cassava granules coated with Newcastle disease virus (NDV) strain V4-UPM was used to vaccinate free-range chickens in their natural habitat. Immune response, vaccine virus excretion and the efficacy of the food vaccine were assessed by standard methods. Results show that out of 218 chickens given initial food vaccine in the four locations, 138 (63.3%) produced detectable HI antibody while 202 (92.7%) had titres < 3.0. However, only 16 (7.3%) attained log2 3.0 with GMT of 3.2. This was made up of Nchara- Akanu 7(12.7%), Vandekya 0(0.0%), Fadan Karshi 1(1.7%), and Turu 8(15.1%) with GMTs of 3.3, 2.9, 3.0, and 3.6 in that order. Following the administration of a booster dose of vaccine on 194 birds in the same flocks, 170(87.6%) sero-converted with 118(60.8%) attaining log2 3.0 and GMT of 9.7. Chickens attaining HI titres up to log2 3.0 from the locations were as follows, Nchara-Akanu 26(51.0%), Vandekya 22 (51.2%), Fadan Karshi 28(53.8%), and Turu 33(68.8%) with GMTs of 12.8, 7.5, 7.0, and 12.6 respectively. Vaccinated birds excreted infective vaccine virus. Out of 55 buyback chickens challenged, 15(27.3%) died while 40(72.7%) survived. Twenty two (22) out of 24 (91.7%) unvaccinated birds challenged died and only 2(8.3%) survived. It is therefore concluded that cassava granules could be good carrier for food-borne ND vaccine delivery to village chickens in Nigeria.