One diaper for a baby goat made from one of our toddler diaper covers... cheap, easy and works surprisingly well! The inserts are newborn prefolds (locally for sale at Mama Goose, downtown Ithaca) which I launder together with my toddlers' diapers. The diaper cover is slightly altered: I cut off the two velcro side taps (saved some of the border to sew around the cut edge), removed the velcro pieces and sewed those back on along the top edge. This way it is a wrap - or as the male wrap I got at PetSmart for $20 said; it nicely covers the male countours...
As you can see, it is comfortable enough to be able to have nice, long naps in front of the woodstove...