DETERMINATION OF NEWCASTLE DISEASE VIRUS ANTIBODY TITRE IN VACCINATED AND UNVACCINATED POULTRY BIRDS WITHIN KADUNA SOUTH LOCAL GOVERNMENT AREA KADUNA STATE, NIGERIA

Abstract

Newcastle Disease Virus (NDV) is a major threat to poultry health worldwide, leading to significant economic losses. This study aims to determine and compare NDV antibody titres in vaccinated and unvaccinated poultry birds, assess biosecurity practices, and identify risk factors associated with the disease within Kaduna South L.G.A., Kaduna State, Nigeria. Two hundred serum samples were collected from vaccinated and unvaccinated birds from 20 poultry farms to determine their antibody titres using Haemagglutination Inhibition (HI) tests. The results showed that vaccinated birds had significantly higher mean antibody titres (512-4,096) compared to unvaccinated birds (64-2048), with some unvaccinated birds, particularly day-old chicks, showing transient protective titres due to maternally derived antibodies. Seropositivity rates were significantly higher in vaccinated birds (100% ± 5.37%, range: 20-100%) than in unvaccinated birds (64% ± 39.29%, range: 0-100%). However, the immune status of most unvaccinated birds was inadequate, highlighting the importance of vaccination in achieving long-term immunity. Bio-security and bio-safety information from structured questionnaires revealed that most farms adhered to certain practices, such as controlled access (95%) and proper feed storage (100%). In comparison, critical gaps were observed in low vaccination uptake (65% of farms did not vaccinate) and poor vehicle disinfection (10%). Risk factors such as poor vaccination compliance, inconsistent disease monitoring, and improper manure management were identified as major contributors to infection vulnerability, particularly in commercial layer birds. The study concludes that vaccination programs, identified risk factors, and enhanced bio-security measures are essential for effective NDV control.