Description of Light Environment in Broiler Breeder Houses with Different Light Sources—And How It Differs from Natural Forest Light

SIMPLE SUMMARY: As modern chicken production is based on keeping the birds indoors in buildings without windows, the artificial light environment is one of the key factors affecting their welfare and production. This paper aims to describe the light environment in nine broiler breeder houses with one of three different light sources (LED light, compact fluorescent lights or LED with UVA) using two different light assessments: spectrometer and the environmental light field (ELF) method. The paper also aimed to describe how the artificial light compares to the light in forest habitats. The results show that the light environments were relatively similar between the nine breeder houses and were typical for indoor environments. The artificial light environment differed significantly from the forest habitats, including a higher intensity even in the dense forests, a larger range of intensities in the natural environment (i.e., less bare) and a difference in the spectral balance between the forest and the breeder houses. The forests had roughly equal amounts of red and green, with a characteristic switch to more green than red in the upper part of the environment. The implications of these results, together with several potential improvements to the artificial light environment, are discussed. ABSTRACT: Light is a key factor in poultry production; however, there is still a lack of knowledge as to describing the light quality, how to measure the light environment as perceived by birds, and how artificial light compares with the light in the natural forest habitats of their wild ancestors. The aim of this study was to describe the light environment in broiler breeder houses with three different light sources, using two different methods of light assessment. We also aimed to compare an artificial light environment with the light in a range of relevant natural forest habitats. A total of 9 commercial broiler breeder houses with one of three different light sources—Lumilux 830 CFL (n = 3), Biolux 965 CFL (n = 3) or LED Evolys with UVA (n = 3) were visited. Assessments of the light environment in the breeder houses were conducted using both a spectrometer and the environmental light field (ELF) method. ELF measurements from three forest types in south India (Kerala) were also included. We found that most aspects of the light environment were similar between the nine breeder houses and were not dependent on the type of light sources. The only clear difference related to the light source was the spectral balance, wherein 830 CFL had the most red-dominated light, 965 CFL had the most blue-dominated light and Evolys was intermediate but with more UV than the latter two. Plumage color had minimal effect on the light environment. Both the spectrometer and the ELF method provided valuable information. The spectrometer gave detailed values about certain aspects of the light environment, while the ELF described the light more in line with human and avian visual perception. We also found that the light environment in the investigated broiler breeder houses differs dramatically in all measured aspects from the natural light habitats of wild junglefowl, suggesting improvement possibilities in artificial lighting systems.