Influence of light sources on body characteristics of female Japanese quail (Coturnix coturnix japonica) in different reproductive ages

The aim of the study was to evaluate the influence of different light sources on organ characteristics, bone development, chemical body composition and hepatic function of female Japanese quail (Coturnix coturnix japonica) in different reproductive ages. In total, 210 female 1-day-old birds were housed in a brick shed, which was divided into six rooms during 12 weeks. Each room was equipped with a different type of light bulb (incandescent; compact fluorescent; and white, blue, red and green light-emitting diodes (LEDs)) and contained seven cages with five birds in each. The light intensity was 15 lx and the photoperiod was 23 h light and 1 h dark (23L:1D) during the first week, 10 L:14D from the second to the fifth week, and 17L:7D until the end of the experiment. The experimental design was completely randomised, with six treatments and seven replicates of each bird. The morphophysiological conditions of the birds were evaluated at the beginning (8 weeks) and during peak production (12 weeks). At 8 weeks, a higher intestine weight and length and liver weight were observed in birds maintained in white LED (P < 0.05). Lower breast weight (P < 0.01) was also observed with this type of lamp. White and red LEDs decreased (P < 0.05) the percentage of ash in the tibia, but this reduction did not affect (P > 0.05) bone resistance. At 12 weeks, higher bone resistance was obtained (P < 0.01) with white LED and higher eye diameter was observed (P < 0.05) with incandescent and white LED lamps. There was no influence (P > 0.05) of light sources on the circulating levels of aspartate aminotransferase and alanine aminotransferase. Fluorescent bulbs resulted in the highest (P < 0.05) level of γ-glutamyltransferase, while blue LED resulted in the lowest level. There was no influence (P > 0.05) of light sources on chemical body composition in any of the evaluated ages. It was concluded that the photostimulation of Japanese quail with white LED is more efficient to stimulate their organ development, especially the intestine, until 8 weeks of life, resulting in birds with better bone development during peak production.