Point Seroprevalence of Chicken Anaemia Virus and Infectious Laryngotracheitis Virus in Village and Commercial Poultry Systems in Selected Areas of Central and North Western Provinces of Sri Lanka

The poultry industry in Sri Lanka plays a crucial role in economic development and nutritional security. This study aimed to evaluate point seroprevalence and risk factors of chicken anaemia virus (CAV) and infectious laryngotracheitis virus (ILTV) in village chickens within the Central Province, and also assess the point seroprevalence of ILTV in commercial layers from the Central and North Western Provinces. A cross-sectional survey and serological assessment were conducted at village chicken farms in the Central Province, and 48 blood samples were collected for antibody detection. Additionally, 311 blood samples from commercial layer flocks in Central and North Western Provinces were tested for ILTV seroprevalence. Chi-square tests were performed to identify associations between antibody prevalence and risk factors. Semi-intensive rearing was predominant (75%), with only 18.75% of farmers vaccinating (for Newcastle disease) their flocks and 37.50% practicing deworming. Nutritional supplementation varied, 50% providing calcium and 62.50% providing vitamin supplements. Despite 68.75% of farmers consulting veterinarians, significant health challenges persisted. Serological analysis indicated a high prevalence of CAV (87.50%) and ILTV (66.67%) in village chickens. CAV seroprevalence was significantly associated with flock size (P = 0.04) and veterinary consultation (P = 0.05). Seroprevalence of ILTV in village chickens showed no significant associations with risk factors. In contrast, ILTV seroprevalence in commercial poultry was markedly lower, with the prevalence rates of 13.26% in the Central Province and 5.63% in the North Western Province. The study highlights the multifaceted challenges in village poultry farming, including high disease prevalence, limited vaccination coverage, and nutritional deficiencies, and suggests that poultry farming can be strengthened by addressing these gaps.