The laminate I've dealt with (admittedly, older versions, I don't know for sure if it's still made the same) has a MDF-type base that does not have any sense of humor at all about getting wet. In a chicken coop, you can pretty much figure that at some point dampness WILL seep in thru the cracks. At which point your floor will swell, buckle, and begin to disintegrate.
I'd recommend skipping it. For one thing it has ZERO advantages over just properly primed and painted plywood, which is a perfectly fine flooring, no need to put anything ON it
I'd also say it'd be better to stay away from anything with cracks in it. It will just make it harder to clean. If you're wanting something smooth like laminate to make it easier to clean, I'd suggest using linoleum.
I brought back a STACK of old laminate flooring that was removed from a reno project I was helping with.
Now I'm wondering what else I can do with it...