"У его брата есть курица."

Translation: His brother has a hen.

[shauntdrobeck]

why can this not be "his brother has chicken?"

[Apahegy]

It can be. Курица means both chicken as well as hen.

[evgeny-ar]

Because of the missing article I guess

[moonintensifies]

Is there a word in Russian that means "rooster"?

[Kundoo]

I guess you know it by now, but in case if anyone else is wondering, It's "петух".