Serological Survey of Dominant Viral Diseases (Newcastle Disease (ND), Infectious Bronchitis (IB) and Infectious Bursal Disease (IBD)), in Broilers Flocks in Northern Algeria

The present study was conducted to survey about sero-epidemiological status of Newcastle disease (ND), Infectious bronchitis (IB) and Infectious bursal disease (IBD) on Algerian broiler chicken (30 flocks/1200 sera) using ELISA method and to assess the influence of some risk factors related to each disease. Among all investigated flocks, ND was the most seroprevalent disease (63.33%); however, IB and IBD showed less serological positivity (40% and 16.66% respectively). For ND, Cobb 500 Flocks were significantly more seropositive by 78% (p = 0.025) than other strains. Nevertheless, flocks with good hygiene were significantly less seropositive to ND by 26% (p = 0.022). For IB, the risk of seropositivity was significantly lower in spring by 40% (p = 0.036). Although, flocks with higher density or with more than 30 days old were more seropositive respectively by 47% (p = 0.041) and 45% (p = 0.019). At last, when broiler chicken were not boosted by IBD vaccine, flocks appeared to be more seropositive by 48% (p = 0.047); especially in spring by 45% (p = 0.048); or in farms with poor hygiene by 65% (p = 0.004); however, more than flocks 30 days old flocks were less seropositive by 30% (p = 0.009).