Evaluation of spray and oral delivery of Newcastle disease I2 vaccine in chicken reared by smallholder farmers in central Ethiopia

Abstract

BackgroundNewcastle disease (ND) is a highly infectious disease causing considerable economic losses to poultry farmers worldwide. Conventional vaccine delivery methods are not suitable for smallholder and rural poultry producers, and thus appropriate vaccination methods need to be sought. This study was carried out with the main objective of evaluating the efficacy of ND I2 vaccine delivered via drinking water and spray under smallholder farmers’ condition in Minjar-Shenkora district, central Ethiopia. Twenty households were randomly assigned to intervention and control groups. Chickens owned by the selected households were randomly assigned to one of the three intervention groups. Blood samples were collected regularly for antibody assay from individual chicken vaccinated with ND I2 vaccine using different routes.ResultsAt baseline, there was no difference in antibody titer among the experimental groups. After the first and booster vaccinations, the three vaccinated groups had significantly higher antibody titer (P < 0.001) than the unvaccinated control group. Interestingly, there was no statistically significant difference in antibody titer among the vaccinated groups. Out of the 40 chicken in the unvaccinated control only 14 had antibody titter≥ log23. Similarly 19/37 of chicken in the drinking water group, 19/37 of chicken in the eye drop group and 20/40 chicken in the spray group had antibody titer ≥ log23. Two weeks after the first vaccination the proportion of chicken with antibody titer ≥ log23 rose to 23/37, 30/37 and 29/40 in the group vaccinated via drinking water, eye drop and spray, respectively. The proportion remained low in unvaccinated group. Hundred percent of the vaccinated chicken survived after infection with the virulent ND virus (Alemaya strain); whereas only 40% survived from the unvaccinated control group.ConclusionThe results of this study showed that ND I2 vaccine administered via drinking water and spray under smallholder farmers’ situation provoked protective antibody level similar to the eye drop method. The use of ND I2 vaccine could contribute to food security if used by rural poultry farmers properly.

Follow up the antibodies titer against Newcastle disease virus in broiler breeders using ELISA test

“…The use of inactivated vaccine against ND in broiler breeder is required and its should be used earlier than point of laying period. Also, for avoidance the loss of egg trait, egg production, hatching and to achieve extreme level of antibodies titer in broiler breeder flocks (19). In this study the titer of antibodies was elevated suddenly and reach to high level 37512±2049.4 at 20-1 week/day of age and this elevation of titer was due to the rolling or circulating of field virus within the flock with on obvious clinical signs (subclinical infection) or may have donated to the fact that existing vaccines and vaccination programs are not maximally efficient in avoiding the transmission of infection (20) and it was described that vaccination campaigns of poultry against ND can only protect the birds from the more severe consequence of highly pathogenic (velogenic) NDV, but not from infection and replication of the virulent strains of virus (21).…”

Newcastle disease and its different applicable control options in poultry in Ethiopia

“…It can be delivered by the oral route and can be applied by unskilled personnel under field conditions. Several studies confirmed that the V4 vaccine is highly protective when given by conventional routes (Mebrahtu et al, 2018). The thermo-stable-12 vaccine produced by NVI and was kindly granted by pan African veterinary vaccine center (PAVVC).…”

“…Different in effect of spray and aerosols are caused by the size of droplets, coarse droplets are short-lived whereas fine droplets are long-lived. Vaccination through water can also be used, but give varying results due to the variation in water intake between and among birds (Mebrahtu et al, 2018).…”

“…Moreover, it is highly variable from farm to farm and among the different production systems. For instance, the sanitary and management control measures were not efficient and have contributed significantly to the occurrence and severity of series of outbreaks of ND from 1983-1995 in three sate poultry forms in Ethiopia (Yune and Abdela, 2017;Mebrahtu et al, 2018).…”

“…In fact, it has been argued that Newcastle disease may represent the biggest drain on the world economy than any other viral disease (Alexander and Jones, 2003). In Ethiopia the disease known to cause heavy losses in village chicken as compared to commercial poultry farms (Mebrahtu et al, 2018). This is because, unlike commercial chicken, little efforts have been made to control Newcastle disease in Ethiopian village chickens (Desta and Wakeyo, 2012;Bogale et al, 2017).…”