Influence of blue, yellow, and red light spectra on growth performance and physiological development of Japanese Quail (Coturnix japonica) under a floor-based rearing system.

This study evaluated the effects of different LED light spectra (blue, red, and sunlight/yellow) on the growth performance of Japanese quail (Coturnix japonica) reared on the floor. A total of 300 quails age in day 33(235 females, 75 males) were used. Until week 5, all birds were kept under uniform sunlight to eliminate confounding light related stress. During week 6, they were assigned to sunlight (yellow), blue, or red light groups under controlled conditions (24 ± 1 °C, 55-60% humidity). Body weight was recorded weekly, and data were analyzed using ANOVA and Tukey's HSD to determine treatment effects. Machine learning (ML) algorithms Linear Regression, Random Forest, and XGBoost were applied to predict growth trends and assess model accuracy. Blue light significantly increased body weight (p < 0.001) at week 6, averaging 298.5 ± 3.2 g, followed by sunlight (284.2 ± 2.8 g) and red light (271.6 ± 4.1 g). A notable Gender × Light interaction (F = 29.23, p < 0.001) showed females responded more positively to blue light. After lighting treatments, the female-male difference reached 50.3 g, while none was observed earlier (p > 0.38). Among ML models, XGBoost performed best (R² = 0.90, RMSE = 3.7 g), followed by Random Forest (R² = 0.84). Blue light improved growth and produced calmer behavior, whereas red light reduced performance. Applying blue light during the growing phase and sunlight during laying appears optimal for productivity and welfare. Future work should test hybrid spectra with gradual color transitions under farm conditions.