Our observations with dark house broiler operation in Sri Lanka (one close house broiler operation with 6 cages, two of which are dark houses) are as follows; as the sunlight is blocked completely, temperature within the cage remains lower than that of a normal curtained house which results in lower electricity bill, In dark houses, we use CFL bulbs which consume less energy though the bulbs are switch on through out, Final weight gain is always about 50 to 75g more that the normal curtained close house. Birds are calm.
Dear T.M. El-Sheikh,
You can find the article Broiler Dark House- American Experience by Dr. Gates on Engormix. Please click on the title.
Enjoy the reading!