Not a Recognized Botanical Term
"Cow grass" is not a recognized botanical term, so it is difficult to say for sure what you are referring to. It is possible that it is 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.
Help Me Identify What You Mean
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.