Goats don't eat cans, but will nibble on just about anything. I had several pygmy goats that didn't believe in fencing and would get out every chance they got. They did chew the licenese plate cover and plate off my husbands truck! But no, they don't chow down cans like the old movies used to show. (Goats actually have very sensitive stomachs!)
They stripped the bark off several apple trees, cherry trees and a pear tree which didn't thrill my husband, so for their sake and our sanity, we gave them to a neighbor that has a petting zoo.