Hi! I have two female piggies who are 1 year old (adults i guess?) Anyway, I?ve decided to try to buy farm hay instead of store bought hay, but it?s really expensive. The problem is I just don?t know how much to order in pounds. I think I am gonna order from small pet select, I just don?t know how much to get (in pounds.) I?m looking around to buy one each month, so could anyone tell me how many pounds my piggies would eat in a month? thanks!