Serological, clinical, and risk factors of the Newcastle disease on broilers flocks in Algeria

Abstract

Aim: The work aimed at studying the serological and clinical factors, as well as the risk factors of the Newcastle disease (ND) on broilers herds in Algeria. Materials and Methods: A sample of 1248 birds was randomly selected from 52 broiler flocks. We took blood samples from each bird at the level of the wing vein area where an indirect enzyme-linked immunosorbent assay technique was carried out through the use of an IDvet kit. Results: The flocks showed 82.69% of seroprevalence. Clinically speaking, the most common symptoms were sneezing, rale, greenish diarrhea, torticollis, and motor discords. Most commonly observed postmortem lesions were the proventriculitis, tracheitis, and enteritis. Especially, the caeca are hemorrhagic. The scores show the effect of risk factors. There was a significant effect on the mortality, the hygiene and vaccination groups on antibody titers in time 2. The antibody titers were elevated in the herd that recorded a high mortality (more than 10%) compared with those which recorded a low mortality (<10%) (p=0.002). Therefore, the antibody titers were elevated in herds with bad hygiene, compared with the ones with good hygiene (p=0.04). At last, when broiler chicken were not boosted by ND vaccine, flocks appeared to be more seropositive (p=0.02). Conclusion: The serological survey conducted in this study provided an important scope for ND as a dominant viral disease in broilers. Many factors are responsible for the onset of these diseases; correct biosecurity measures are needed to reduce the impact of this pathology in poultry farms.

Indicators and risk factors of infectious laryngotracheitis in layer hen flocks in Algeria

“…On the one hand, the immune response is estimated by the level of specific antibodies produced against the wild virus or the vaccine strain. On the other hand, the protected flocks must have a high average of antibody titers for the baseline resulting from vaccination, with the absence of specific clinical signs [8,10,11,19].…”

“…Two samples were collected from the selected hens from each farm according to the method described by Salhi et al [10] and Messaï et al [11]. The first was performed after the appearance of the first clinical signs.…”

“…The ELISA technique was carried out, as described in the literature [10,11]. Means of titers and the CV were automatically calculated using the software IDSoft™ 5.05 (Montpellier, France).…”

Factor Influences for Diagnosis and Vaccination of Avian Infectious Bronchitis Virus (Gammacoronavirus) in Chickens

“…The serology titer is occasionally given higher trends, but it cannot match with clinical signs; therefore, IBV confirmation is problematic. Thus, conformation diagnosis is based on the accumulation of data from farm records, including egg quality with production graph, mortality, seroconversion or antibody levels, vaccination report, and blood serology, which are clinical signs that concurrently match symptoms of IBV chickens through PM lesions [ 31 , 32 , 33 ]. Sample collection for IBV isolation is best when immediately achieved, as clinical signs are obvious.…”

Determinants of Newcastle disease in commercial layer chicken farms in two districts of Bangladesh: A case-control study

“…This disease is capable of causing 100% mortality in non-vaccinated chicken ( Zhang et al., 2011 ). A number of determinants such as cleaning of farm once a week or never practiced ( Chaka et al., 2013 ), multi-age production system ( Jaganathan et al., 2015 ), poor biosecurity and insufficient vaccination program ( Messaï and Salhi, 2019 ), access to visitors ( Alsahami et al., 2018 ), contact with migratory wild birds ( Otim et al., 2007 ), were shown to have influence on the occurrence of this disease.…”