Let there be light: Early exposure to UV aids broiler behavior, performance

Adding windows to poultry houses is an inexpensive way to improve the environment for broilers and possibly improve productivity, according to Rachel Lynn Dennis, PhD, assistant professor at the University of Maryland.

Ultraviolet (UV) light is a part of natural light, which birds use for social cues and for feeding. However, most traditional houses do not have windows and provide white light only, she told Poultry Health Today.

Dennis was curious about the effects of UV light on broilers when they’re exposed at different stages of development and, consequently, designed a study with 4 groups of birds:

• Birds with UV light only for the first 3 weeks of life
• Birds with UV light only at weeks 4 and 5 of life
• Birds with UV light for the entire 5 weeks starting at day-of-age
• Birds with no UV light

All groups had the same white light in their environment. Chickens with UV light consistently ate more and didn’t forage in areas with no food compared to those with only white light, she said.

UV light reduced the birds’ “fear response” — they didn’t move far away when a new person walked into the house, which they did with only white light. That’s positive, Dennis said, because it’s not good for birds to be easily startled, which can lead to running and injuries.

She concluded that broilers prefer UV or UV/white light to white light only.

The study also revealed differences based on when UV light was introduced. Exposure throughout the growing period made birds more comfortable with different intensity levels of white light. Birds with UV light only for the first 3 weeks preferred low-intensity white light. Birds exposed in weeks 4 and 5 preferred high-intensity white light, Dennis said.

Providing birds natural UV light enriches the birds’ entire environment — they get to see more of it, she said, and noted that some companies are adding windows to poultry houses.