Your pole barn sounds big! Will it’s use be for more than bunnies and chickens? If so, can you explain more about your set up.
as for a metal building, there can be drafts coming between the panels in higher winds. If you are setting up cages around the wall, you are looking to mitigate the drafts. You could staple heavy shower curtains or plastic sheeting around the walls, to the height of cages and replace as needed. Our birds don’t pay much mind to plastic like that. If you are looking for a more permanent solution, metal panels aren’t too expensive and can be cut to the length you want for no extra charge - you are paying based on sqft. You can add paper backed Fiberglass insulation or styrofoam rigid insulation behind a durable material such as Corrugated metal or OSB.
ventilation is important. With that large of a building, I’m guessing the roof is up higher, and there are roof vents etc. but can you tell us how it is ventilated?
we are finishing a project of insulating a workshop in a metal building. We first stuffed stainless steel wool into all spaces created by the corrugated metal at the bottom of the framing to help prevent rodents from coming in for the winter and cozying up inside the insulation. We stapled paper backed fiberglass insulation to the studs. The lower wall has corrugated metal siding, the upper part has painted OSB. However, no animals (except the barn cat) are in the workshop.
