Chinese research reveals that lighting programme can affect the antioxidant status and non-specific immunity of broilers although the birds’ growth was not affected in this study.
A new study conducted by L. Zheng of Zhejiang University and co-authors there and at Wenzhou Medical College and Zhejiang Xinxin Feed Co. Ltd investigated the effects of different lighting regimens on broiler growth performance, antioxidant status and non-specific immunity.
The paper, published in Journal of Applied Poultry Research, describes how a total of 630 one-day-old Lingnan Yellow broilers were randomly divided into three treatments, each with three replicates each (70 birds per replicate).
Lighting schedules were constant lighting (CL), 24L:0D, and two intermittent lighting programmes (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 to 21 days) and finisher (22 to 50 days).
No differences between treatments in growth performance were found.
Compared with CL, INL significantly increased serum melatonin both at days 21 and 50, especially the INL I treatment. Intermittent lighting significantly enhanced the total antioxidant capability in liver at 21 days and the activity of total superoxide dismutase on day 50 in serum and day 21 in liver was significantly higher than CL.
Additionally, INL markedly increased the activity of glutathione peroxidase both in liver and serum on days 21 and 50, and markedly reduced maleic dialdehyde concentration in liver.
The index of thymus (g per kg bodyweight) was significantly elevated under INL on day 21, and the index of bursa of Fabricius (g per kg bodyweight) was also significantly increased under INL II on day 50. Moreover, broilers under INL had higher phagocytosis index.
Zheng and co-authors concluded that in contrast with CL, INL can improve a broiler’s antioxidant status and non-specific immunity but not growth performance. They added that INL II showed a greater effect on antioxidant status and non-specific immunity than INL I.
Zheng L., Y.E. Ma, L.Y. Gu, D. Yuan, M.L. Shi, X.Y. Guo and X.A. Zhan. 2013. Growth performance, antioxidant status, and nonspecific immunity in broilers under different lighting regimens. J. Appl. Poult. Res. 22(4):798-807. doi: 10.3382/japr.2012-00713