Biosecurity Measures and Their Determinants in Commercial Layer Chicken Farms in High Density Provinces of Iran in 2019: A Cross-Sectional Study

Background and Objectives: The commercial layer chicken farming is one of the most important sectors of the poultry industry. This study was conducted to evaluate the status of biosecurity of commercial layer chicken farms in 9 Iranian provinces with the highest layer chicken population.   Methods: In this cross-sectional study, 202 commercial layer chicken farms were selected from nine Iranian provinces in 2019 using stratified random sampling. Then, the required data were collected using a questionnaire by presenting to the farms in person. The results are expressed as mean, standard variation, sum and adoption rate index.   Results: The results showed that the adoption level of total biosecurity measures was 68.18% in the commercial layer chicken farms in Iran. This figure was 72.11%, 75% and 60.82% for conceptual, structural and operational biosecurity measures, respectively. Among conceptual biosecurity measures, the lowest adoption level (29.20%) was for distance to the nearest garden and agriculture land. Among structural biosecurity measures, the lowest adoption level (28.96%) was for a hand disinfection spot before shed. Among the operational biosecurity measures, the lowest adoption level was for water filtrations (31.18%) and microbial testing of water (33.91%).   Conclusion: This study investigated the biosecurity status of commercial layer chicken farms in nine Iranian provinces with the highest layer chicken population and revealed some weaknesses in the implementation of these measures at conceptual, structural and operational levels.