The Effect of Broiler-Targeted Lighting Programs on Productivity, Health, and Welfare.

BACKGROUND

Poultry are highly sensitive to lighting photoperiod, intensity, and color, yet little research has combined these components into a single broiler-targeted lighting program. This study evaluated an integrated dynamic LED lighting program and a further red-light dawn/dusk addition on broiler productivity, health, and welfare.

METHODS

In Experiment 1, 960 male Cobb 500 broilers were reared for 42 d under a conventional white-LED program (CON) or a dynamic blue-emphasis LED program with declining intensity and a gradually shortening photoperiod (i.e., a lengthening dark period; DYN). In Experiment 2, 960 broilers were reared for 35 d under DYN or DYN with a gradual red-light dawn/dusk transition (RDW). Growth performance, tibia strength and ash, intestinal morphology, blood corticosterone, the heterophil-to-lymphocyte ratio, physical asymmetry, tonic immobility, and inversion were measured, and an illustrative income-over-feed-cost analysis was performed.

RESULTS

DYN broilers had higher body weight and lower feed conversion ratio than CON broilers (p = 0.016 and p = 0.003, respectively), together with a lower heterophil-to-lymphocyte ratio, corticosterone, and composite asymmetry (p < 0.05). RDW broilers had greater tibia breaking strengths and lower corticosterone, heterophil-to-lymphocyte ratios, and asymmetry than DYN broilers (p < 0.05), with similar growth performance. Illustrative economic analysis suggested a modest income-over-feed-cost advantage for DYN over CON.

CONCLUSIONS

An integrated, broiler-targeted dynamic lighting program improved growth, intestinal morphology, and stress/fear indicators relative to a conventional program, and adding a red dawn/dusk transition further improved skeletal and stress outcomes without compromising growth, supporting the practical, commercial-scale use of programmable LED technology to improve broiler welfare and productivity.