Characterizing light leakage and spatial variation of illuminance in commercial broiler houses during tunnel ventilation

Providing a suitable lighting environment for commercial poultry is essential for physiological processes, ensuring welfare, and achieving production goals. Recent research has shown that poultry house illuminance (intensity) is dependent on ambient sunlight conditions and that control of light leakage can improve live performance. The objective of this study was to evaluate the performance of fan shades for reduction of light leakage and spatial variation of illuminance in commercial broiler houses. Data collection systems were developed to measure whole house illuminance at a fixed point in time (static) and over a 24-h period (temporal) in a house with and without fan shades. Results from static and temporal testing indicate that fan shades significantly reduce light ingress through tunnel exhaust fans and result in reduced whole-house mean illuminance. Whole-house illuminance uniformity was significantly lower (P = 0.0024) in houses with fan shades (CV = 137.4) than those without (CV = 280.8), and an additional 1.25 h of target illuminance levels (#10 lx) were gained on the day of testing in houses with fan shades installed. Overall, results indicate fan shades are an effective strategy to mitigate light ingress through fans and improve illuminance uniformity within commercial broiler houses.