Effects of Light on Egg Performance and Behaviour in Japanese Quails (Coturnix coturnix japonica)

Lighting period (photoperiod) is one of the most important environmental factors affecting on animals. Thus, we aimed to investigate the effect of lighting period on efficient production performance of Japanese quails under controlled environmental conditions via the egg yield and behavioural characteristics. 48 female and 12 male Japanese quails (Coturnix coturnix japonica) were randomly divided into two groups with two replicates. A scheduled lighting program was applied as 7 Light (L): 17 Dark (D), 6L:18D, 5L:19D, 4L:20D, 3L:21D for five-day periods along 25 days in total using a metal halide lamp with an intensity of light at 41.5 lx to the trial group. At the end of observation, 162 eggs without any damage were obtained from the birds exposed to scheduled lighting program whereas the mean number of damaged eggs/total number of eggs (DE/TE) ratio was 37% in control group exposed to normal daylight length. The number of damaged eggs was correlated with the total number of eggs (p<0.01 vs. control) and egg weight (p<0.0001) in trial group. Egg weight was also found to correlate with body weight (p<0.01 vs. control). During observational experiments any significant difference was recorded in wing stretching, drinking and playing in both groups. However, birds exposed to shortened light headed for less feeding and laying (p<0.05 vs. control) and had leaning to aggressive behaviours such as shouting or stridulating, feather and egg pecking and cannibalism. In conclusion, adding darkness to lighting program contributes energy saving with the equal or even improved production performance in aviaries