What is cow grass?

"Cow grass" is not a recognized botanical term, so it's difficult to say for sure what you're referring to. It's possible that it's a colloquial or regional term for:

* A specific type of grass: Some areas may have local names for grasses that are particularly favored by cows.

* A mixture of grasses: Farmers might use the term "cow grass" to refer to a blend of grasses they sow specifically for cattle grazing.

* A general term for pasture: "Cow grass" could be used to refer to any type of grass growing in a field where cows graze.

To help me identify what you mean, please provide more context:

* Where did you hear the term "cow grass"? A specific location might help narrow down possibilities.

* What is the context of the term? Were you reading about farming, livestock, or something else?

Once I have more information, I can give you a more accurate answer.