Cows know what they like! Ever see some get into a grain or corn field? They will devastate it eating both the grain heads and they stalks. They also eat wild onions and the grain heads of wild amaranth (pigweed). I always worry about cow manure on a garden as pig weed seeds can pass through unharmed and come up in the garden.
Humans know what they like too: Twinkies, slurpies, woopie pies, and cotton candy to name a healthy few.