Does the distribution of light intensity within the barn impact broiler production and welfare?

1. The objective of this study was to determine if rearing broilers under variable light intensity (VLI) impacted their welfare or productivity.2. Ross 308 broilers (<i>n</i> = 7,256) were reared until 35 d of age and exposed to a uniform intensity of 10 lux (CON) or VLI with low intensity areas of 2-5 lux proximal to the walls and high intensity areas of 84-133 lux proximal to feeders.3. The data were analysed as a complete randomised design using an analysis of variance. Significance was declared when <i>p</i> ≤ 0.05.4. Applying VLI resulted in increased feed intake early in life but had no impact on body weight. Overall efficiency was improved in the CON treatment. Mortality diagnoses of skeletal problems were reduced under VLI. Treatment had no impact on footpad, hock or gait score, heterophil to lymphocyte ratio or melatonin concentration. Birds performed certain behaviours in specific locations within the room, independent of light intensity treatment.5. In conclusion, raising broilers under VLI had little impact on production or most welfare parameters assessed in this study. However, satisfying the bird's preference for different light intensities may improve welfare.