Using fully insulated, big sheds are the only way forward - have worked with both traditional huts (boss used to do 150.000 phessies and partridges per season) and had my own set up with big sheds are there are no comparison at all! No backache, better growth rate overall, less loss, % savings on gas (yes, I'm not kidding!). Top quality poults at reasonably price because some game rearers have been able to cut costs drastically and at the same time improve on husbandry.