Laying hens are affected by the intensity, wavelength, and duration of light, and the behavioral patterns of these animals are important indicators of stress. The objective of the present study was to evaluate cluster and unrest behaviors of lying hens submitted to three environments with different treatments of monochromatic lighting (blue, green, and red). For 29 weeks, 60 laying hens from the Lohmann variety were divided into three groups and monitored by surveillance cameras installed on each shed ceiling and directed to the floor. Each group was housed in a small-scale shed and maintained under a monochromatic lighting treatment. The recordings were made at two times of the day, 15 min in the morning and 15 min in the afternoon, and the videos were processed, segmented, and analyzed computationally. From the analysis of the images, the cluster and unrest indexes were calculated. The results showed the influence of lighting on these behaviors, displaying that the birds were more agitated in the treatments with shorter wavelengths. Cluster behavior was higher in birds housed under red light. There was an interaction between the lighting treatments and the thermal environment, indicating that more studies should be carried out in this area to better understand these behavioral changes.

This observational study verified the effects of monochromatic lighting for three monochromatic light spectra on the production and quality of laying hen eggs and blood parameters, as probable indicators of environmental stress. Lohmann®29-week-old birds were divided into groups of 20 animals, housed in three experimental houses with different lighting treatments (blue, green and red), and monitored for 90 days. Were analysed 4,443 eggs, and the values of the following measurements were extracted: egg weight (g), albumen height (mm), shell resistance (kgf/cm²), shell thickness (mm), Haugh unit, specific gravity (g/cm³), and egg shape. Blood samples were collected from the birds at the beginning and at the end of the study period. The levels of total plasma protein and the heterophile/lymphocyte ratio remained within the normal range. Laying hens housed under blue and red lighting had higher egg production (per hen) and showed better egg quality results. Red lighting stood out for providing significantly better shell resistance than other treatments. Glucose differed between treatments, with a drop in blood glucose levels as the environment light wavelength increased. The quality of the eggs was affected differently by the sources of monochromatic lighting. Correct lighting management promotes better health for birds and increased egg production and quality.