Effect of a Broiler-Specific Light Spectrum on Growth Performance and Adrenocortical Activity in Chickens : A Pilot Study on a Commercial Farm

Light, among the environmental parameters, is a key factor for the well-being of broiler chickens in modern farming. It has the potential to influence a variety of physiological, immunological, and behavioural processes. In this study, we propose the use of a broiler-specific light spectrum, which is a combination of blue, green, and red LEDs, for chickens reared under commercial systems. We evaluated its effects on productivity performance and non-invasive indicators of hypothalamic-pituitary-adrenal (HPA) axis activity. Our findings suggest that the use of broiler-specific lighting significantly improves productivity performance, as indicated by the final mean body weight and uniformity index. While the analyses of droppings and feathers were feasible, further research involving replicates, sampling at multiple time points, and behavioural observations is needed to confirm their role as welfare indicators in farmed chicken. This study evaluated the effect of a broiler-specific light spectrum on productive performance corticosterone (fCC) and androgen dehydroepiandrosterone (fDHEA) concentrations in feathers, and glucocorticoid (GCMs) and androgen (AMs) metabolites in droppings of broilers. Two groups of female Ross 308 broilers were reared under white LED (WL, n = 9000) and broiler-specific LED (BSL, n = 9000) lights. The body weight (BW) of 150 randomly selected animals/groups was measured weekly. Droppings and feathers were collected at the end of the cycle (29 days) from 20 animals/group. The BSL group showed higher final BW than WL (1407 ± 11 vs. 1341 ± 15 g, respectively; p < 0.001) and higher indices of uniformity (76.8% vs. 61.2% animals in the 10% around the mean, respectively; p < 0.001). No difference between groups was found in fCC and fDHEA concentrations or in the fCC-fDHEA, indicating similar long-term HPA axis activity during the cycle. A higher concentration of GCMs was found in the BSL group, indicating higher glucocorticoid secretion before sampling, with neither a difference in AMs nor ...