the number of eggs laid during the last 3 d of the experiment
(wk 22) was divided by 75 (25 hens × 3 eggs)
and multiplied by 100.
The trial was conducted in accordance with the principles
and specific guidelines presented in the Guide for
the Care and Use of Agricultural Animals in Research
and Teaching (FASS, 2010). All 16 groups under red
or green light were sold at the end of the trial. Eight
groups under white light took part in an additional
experiment for 4 wks.