Technically you could “milk” a cow by removing the milk from the udder. I’m not sure if the teat would dispense milk once the body was cooled to a certain temperature, but you could remove the milk using a needle, up to the point where it starts curdling inside the udder…
You can strip a little milk from th\e udder of a dead animal, but not much at all. Wildlife rescuers sometimes try to do this when a mother animal gets hit by a car and leaves an orphan, for example.