What do you call a cows behind?

You can call a cow's behind a few things, depending on how formal or informal you want to be:

Formal:

* Rump: This is the most scientific and neutral term.

* Posterior: This is another scientific term for the back end.

Informal:

* Buttocks: This is a common, everyday term.

* Tail end: This refers to the area around the tail.

* Back end: This is a general term for the rear of the cow.

* Behind: This is a simple and informal term.

You can also use more playful terms like:

* Moo-moo: This is a silly and affectionate term.

* Booty: This is a slang term, but it can be used humorously.

The best term to use will depend on the context of your conversation.