This study was conducted to evaluate the
effect of monochromatic light stimuli during embryogenesis
on breast muscle growth, chemical composition,
and meat quality of male broilers. Fertile broiler eggs
(Arbor Acres; n = 1,320) were preweighed and randomly
assigned to 1 of 3 treatment groups in 3 modified
incubators: 1) control group (in dark condition),
2) monochromatic green light group (560 nm), and 3)
monochromatic blue light group (480 nm). The monochromatic
lighting systems sourced from light-emitting
diode lamps and were equalized at the intensity of 15 lx
at eggshell level. After hatch, 120 male chicks from each
group were placed in 6 replicates with 20 birds each.
All of the birds were housed under white light (30 lx
at bird-head level) with a light schedule of 23L:1D. At
21, 35, and 42 d of age, BW and breast muscle weight
in the green light group were significantly increased
compared with birds in the blue or dark groups (P
< 0.05). The breast muscle weight and breast muscle
percentages in birds incubated under green light were
significantly elevated by 50.39 g (0.76%) and 54.07 g
(1.20%) than those in the dark condition or blue group
at 42 d of market age (P < 0.05), respectively. In the
green light group, feed intake during 0~42 d was higher
than that in the other 2 treatment groups (P < 0.05);
feed conversion ratio during 0~35 and 0~42 d were
lower than that in the dark condition (P < 0.05). No
significant differences in the contents of breast moisture,
CP, crude fat, and crude ash among all groups
were observed (P > 0.05). Green light stimuli tended
to increase cooking loss (P = 0.08) and L* value of
24-h meat color (P = 0.09). These results suggest that
green light stimuli during embryogenesis enhanced the
posthatch BW of male broilers, increased breast muscle
growth, and improved the feed conversion ratio, but it
did not cause any noticeable changes in breast chemical