Impacts of HVT Vaccination Against Marek’s Disease in Broiler Chickens in Algeria

Document Type : Original Articles

Authors

1 PADESCA Laboratory, Institute of Veterinary Sciences, University of Mentouri Brothers, Constantine, Algeria.

2 Institute of Veterinary Sciences, University Saad Dahlab Blida 1, Blida, Algeria.

10.32598/ARI.81.1.3672

Abstract

Introduction: Marek’s disease (MD), a lymphoproliferative and immunosuppressive viral disease of poultry, poses serious challenges to broiler production worldwide. Vaccination with turkey herpesvirus (HVT) is a common preventive strategy. This study aimed to evaluate the zootechnical and economic impacts of HVT vaccination in broiler chickens reared under field conditions in northeastern Algeria.
Materials & Methods: The trial was conducted in the Mila Region over six weeks and involved two cohorts of 11,000 broiler chickens each: A vaccinated group (VG) receiving HVT vaccination on day 1 in addition to standard vaccinations, and a non-vaccinated group (NVG). Both groups were sourced from the same breeder stock and raised under identical management and environmental conditions. Key parameters measured included average body weight (BW), feed conversion ratio (FCR), and weekly mortality. Economic viability was assessed through a cost-benefit analysis (CBA), considering vaccination costs (218.66 EUR) and estimated production gains.
Results: From week four onward, VG birds showed significantly higher BW than NVG, reaching 3070 g vs 3000 g at week six (P<0.001). FCR remained comparable between groups, with VG showing slightly improved efficiency from week three, though not statistically significant (P=0.93). Mortality rates (MR) were significantly lower in VG from week three onward, with pooled analysis confirming a protective effect of vaccination (P<0.01). The improved growth performance and reduced mortality observed in the VG suggest a clear health benefit of HVT vaccination in broilers raised under field conditions. Despite no significant difference in feed conversion efficiency, the biological impact of the vaccine was evident from mid-trial onwards, highlighting the protective effect of HVT against MD-related losses. HVT vaccination in broilers enhances growth performance and significantly reduces mortality without compromising feed efficiency. Economically, it proves to be a highly viable strategy, resulting in a net benefit of 5489.74 EUR per flock and a cost-benefit ratio of 26-to-1. 
Conclusion: These findings support the integration of HVT vaccination into comprehensive health management programs in intensive poultry systems.

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