Previous reports have suggested that
green light enhances broiler growth at an early age,
whereas blue light enhances growth at older ages. The
aim of this study was to examine the effect of a switch
in monochromatic light at 2 ages on growth and development
of broilers. Male chicks (Anak, n = 640) were used.
After hatch, chicks were weighed, wing-banded, and
blocked into treatment groups. Chicks were grown in 1-
m2 pens in 8 isolated light-proof rooms (20 birds/pen).
The light treatments were (1) Control white (mini-incandescent
lamps), 2) blue light-emitting diode (LED) lamps,
3) green LED lamps, 4) blue LED switching to green at
10 d of age, 5) blue LED switching to green at 20 d of
age, 6) green LED switching to blue at 10 d of age, and
7) green LED switching to blue at 20 d of age. There were