I'm moving next week with my chickens from Nebraska to Utah. My friend who is driving the Semi hauling my stuff was concerned about Chickens going over the mountain passes. Does anybody know what effect altitude changes will have on chickens? I only have 3 and they will be in cages in the back of my Blazer. We will be going slow because I will be following a Semi. I think they will be fine, but my friend is not so sure. Any advice?