Growth performance, antioxidant status, and nonspecific immunity in broilers under different lighting regimens

Abstract

The present study was conducted to investigate the effects of different lighting regimens on broilers’ growth performance, antioxidant status, and nonspecific immunity. A total of 630 one-day-old Lingnan Yellow broilers were randomly divided into 3 treatments with 3 replicates each (70 birds/replicate). Lighting schedules were constant lighting (CL), 24L:0D, and 2 intermittent lightings (INL), 16L:2D:1L:2D:1L:2D (INL I) and 17L:3D:1L:3D (INL II), which were provided by incandescent bulbs. The trial was split into starter (1–21 d) and finisher (22–50 d) phases. No differences between treatments in growth performance were found. Compared with CL, INL significantly increased serum melatonin both at d 21 and 50, especially the INL I treatment. Intermittent lighting significantly enhanced the total antioxidant capability in liver at 21 d, and the activity of total superoxide dismutase at d 50 in serum and d 21 in liver was significantly higher than CL. Additionally, INL markedly increased the activity of glutathione peroxidase both in liver and serum at d 21 and 50, and markedly reduced maleic dialdehyde concentration in liver. The index of thymus (g/kg of BW) was significantly elevated under INL at d 21, and the index of bursa of Fabricius (g/kg of BW) was also significantly increased under INL II at d 50. Moreover, broilers under INL had higher phagocytosis index. In conclusion, in contrast with CL, INL can improve broilers’ antioxidant status and nonspecific immunity, but not growth performance. Moreover, INL II showed a more significant effect on antioxidant status and nonspecific immunity than INL I.