Biosecurity measures and effects on health performance and antibiotic use in semi-intensive broiler farms in Uganda.

Background: Effective biosecurity measures prevent the spread of pathogens, thereby reducing the need for antibiotic use on livestock farms. However, quantitative data on these practices and health outcomes in semi-intensive broiler farms in low-income settings is limited. A longitudinal study in Wakiso, Uganda, aimed to evaluate biosecurity practices, health performance, and antibiotic use in such farms. Methods: The FarmUSE survey tool was used to collect data from 19 farms over two production cycles. A biosecurity risk assessment tool was used to quantify biosecurity. Blood samples (n = 342) were collected and analyzed using the ProFLOK® assay to assess antibody responses to vaccines for Newcastle disease (NCD), Infectious Bronchitis (IB), and Infectious bursal disease (IBD). Results: Median biosecurity scores were 26.3 % for external measures, 55.6 % for internal measures, and an overall score of 38.5 %. Sixteen farms reported respiratory signs, and 12 had gastrointestinal issues, with median mortality rates of 2.9 % in the first cycle and 4.6 % in the second. Antibiotic use was reported by 84 % and 77 % of farms in the first and second cycles, respectively. The most used antibiotics were tetracyclines, fluoroquinolones, and macrolides, with the highest usage occurring during the brooding phase. Good antibody responses were reported in only 10.5 % of flocks for NCD and 16 % for IBD, while all farms had poor responses against IB. Conclusion: Recurrent clinical signs could be attributed to insufficient biosecurity and inadequate vaccination outcomes, resulting in high antibiotic usage despite low mortality rates. Improving diagnostic access and strengthening the vaccine supply chain are essential. Identifying feasible and cost-effective biosecurity practices for semi-intensive broiler farms can enhance health outcomes, reduce antibiotic use, and boost productivity.