The translation is pretty simple. Apparently "Kokoleoko" is just another way of saying "cock-a-doodle-doo," and "ahby" is "goodbye."
Now, each source I find this song says something different about where exactly it's from. Most often, they say either Liberia or Ghana. So, I've just labeled it as a West African folk song to be more accurate.
Anyway, this song is great for teaching the half note, which I do in 2nd grade. We spend awhile preparing, using songs that have half notes, before actually labeling what they are. This song is also great if you bring it back in the end of 3rd/beginning of 4th, or whenever you teach syncopation.
There is a clapping game that goes with this. It looks more complicated than it actually is. My 2nd graders are challenged by this, but really enjoy doing it. You can watch an example below: