Milk the cow that standeth still

Why buy a cow if you can get the milk for free

I don't care how many pails of milk I lose, as long as I don't lose the cow

Milk the cow, but do not pull off the udder.

He who wants milk should not sit in the middle of a field and wait for a cow to back up to him

I can't say I hate cats, but holy cow, dogs are a horse of another color.