Bulb type doesn’t have much impact on broiler performance

Learn what aspects of a broiler house lighting program affect bird welfare and performance.

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For meat birds, just about any type of white light-producing bulb is OK. (Belyaevskiy | istockphoto.com)
For meat birds, just about any type of white light-producing bulb is OK. (Belyaevskiy | istockphoto.com)

Jody Purswell, Ph.D., research agricultural engineer, U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) Poultry Research Unit said he has looked at every type of light bulb under the sun, and light source doesn’t have a significant impact on bird performance.

“For meat birds, just about any white light is OK,” he said.  

Purswell told the audience at USPOULTRY’s Live Production, Welfare & Biosecurity Seminar in Nashville, Tennessee, on September 17, that light intensity and photoperiod are what have the biggest impact on broiler performance.

A recent review of published research on the impact of light levels found that what Purswell called the “sweet spot” for broiler performance is for the light level in the broiler house to be between 5 and 10 lux (0.46 to 0.93 foot candles).

Increasing light intensity above 10 lux increases bird activity, but it doesn’t improve gait scores. Increased light intensity above 10 lux, even if the light source is natural light, has not been shown to reduce physiological signs of stress.

“Natural light doesn’t seem to affect measurable welfare characteristics,” Purswell said.

He said research has also shown that a minimum of four hours of darkness are needed per day without interruption, and this dark period should be at the same time each day. Increased photoperiod improves gait score but results in worse foot pad condition through 35 days, Purswell said.

Most of the light intensity in a broiler house is not being provided by the light bulbs in warm weather, he said. The light coming into the house though the fan louvers when all the fans are running to cool the birds is of much higher intensity than the light provided by the bulbs. He said that, in a typical 500-foot house, the light coming in from the fan louvers will increase the light intensity of about one-third of the house and birds farther away can also see the brightness at the fan end.

The increased light intensity can result in reduced bird performance. He said fan shades can be used to reduce the amount of light coming in through the fan louvers while only reducing fan efficiency by 1%. While Purswell wouldn’t specifically endorse the use of fan shades, he said it is worth taking steps to properly control light intensity in the broiler house.

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