Physiological variations in male Japanese quail (Coturnix japonica) reared under different light intensities

This study involved exposing male Japanese quail to a gradual increase in light intensity over a 12-week trial period to alleviate the stress induced by high-intensity lighting throughout the rearing phase. In the trial, 60 birds aged 48 days were allocated into four treatments, each consisting three replications, with each replicate containing five birds. The raising facility was designed to meet the unique requirements of the study. The lighting schedules were established, with a standardized 8-hour dark interval. T1 (control): 16 hours of light; T2: 15 hours of light with a 20-minute intensity increase; T3: 14 hours of light with a 40-minute intensity augmentation; T4: 13 hours. The results revealed no significant variations in the blood plasma biochemical markers, such as glucose, protein, albumin, and globulin, across all treatments. A notable rise (P≤0.05) in LDL levels was detected in T3 relative to T1 (control) and T4. Moreover, ALT enzyme levels were markedly elevated (P≤0.05) in T2 and T4 relative to the control group. ALP enzyme levels were markedly increased (P≤0.05) in T3 relative to the control. No significant differences were observed in the relative weights of internal organs across the treatments. Nevertheless, melatonin hormone levels showed a marked reduction (P≤0.05) in T3 and T4 relative to T1. The results indicate that the incremental rise in light intensity alleviated stress, increased avian comfort, and improved certain blood biochemical indicators in male Japanese quail.