- 2016 Gregory S. Archer. Background: The eventual switch to light-emitting diode (LED) light fixtures as the standard in the poultry industry has resulted in the need to reevaluate the standard management practices relating to lighting. Current management practices utilized by the industry are based on research that used lighting fixtures no longer used and therefore may no longer be relevant. One such practice is to raise broiler chickens under dim lighting to maximize growth and minimize stress and fear. Objective: To determine if broilers could be reared under brighter light using LEDs. Methodology: To investigate whether birds could be raised under brighter conditions using LED lighting compared to the traditional incandescent light without negatively affecting growth, feed conversion, stress and fear broilers (n = 120 per treatment) were raised under incandescent (INCAN) or LED lighting at either dim (5 lux) or bright (20 lux) intensity. Growth, feed conversion, fear and stress susceptibility were all quantified. Results: The LED-bright broilers weighed more after 45 days than all other treatments (p<0.05). The INCAN treatments overall had lower 45 days weights and higher 45 days feed conversion than the LED treatments (p<0.05). Intensity did not affect weights or feed conversion. The INCAN treatments exhibited more fear than the LED birds though the INCAN-dim birds behaved similarly to the LED treatments in tonic immobility. The INCAN treatments showed more stress susceptibility than the LED treatments (p<0.05). Conclusion: These results indicate that it is possible to raise broilers under brighter light when using LEDs without lowering growth or efficiency and still attaining the positive benefits of LED lighting on fear and stress.