This study evaluates the immunization status of free-range local chickens (FRLC) following a mass vaccination program against Newcastle disease virus (ND) that was carried out in Mvomero district, Morogoro, Tanzania. Six villages from two wards (one trial and one control ward) were involved. A total of 819 chickens from the two wards were tested by haemagglutination inhibition (HI) for ND antibodies following I-2 vaccination in the trial ward. The vaccine was administered to FRLC by eye drop in trial villages by trained community vaccinators while chickens in the control villages were not vaccinated. Birds with HI antibody titres equal or greater than 23 (HI≥23) were considered immune. The percentage of birds in each age category with protective NDV antibodies in the trial ward were chicks (25.3%), growers (53.3%) and adults (84.8%), while the percentage in the control ward were chicks (14.0%), growers (30.1%) and adults (40.4%). The percentage of immune chickens by age categories in the trial ward were significantly higher (p<0.05) compared to immune birds in the control ward. The current study indicates that the National vaccination regime is more successful in growers and adults versus chicks. In order to improve flock protection against ND, the vaccination program should cover chicks. This can be achieved if farmers schedule a special vaccination program for chicks and harmonize hatching to conform to the vaccination regime.
|Original language||English (US)|
|Journal||Livestock Research for Rural Development|
|State||Published - Jul 1 2012|
- Newcastle disease
- Thermostable vaccine
- Village chickens