There are a lot of strange things you can come up with when you play around with road signs. I like this idea, because if you've ever hung out with cows, this is pretty much what they do all day.
A couple of summers ago we cow-sat for my in-laws while they were out of town. The cows always ran away from me when I went up to the field to fill the water trough and bring up hay, but if I ever went outside without bringing them hay, they'd bellow and whine interminably. Cow Nirvana is to process hay from one end to the other.