George, the literal translation posted by Joe Offer in the thread you linked to above is accurate, so I'd say the "poetic" words are fairly close to the original. Here's that literal translation; see what you think.

In a wagon lies a calf; it is tied with a rope. High in the sky a swallow soars, is joyous, and runs back and forth.

The wind laughs in the cornfield, laughs and laughs and laughs. It laughs a whole day and half the night. Dona, Dona, Dona...

The calf cries and the farmer says: Who told you to be a calf? You could have been a bird, you could have been a swallow.

Poor calves are bound and dragged and slaughtered. Whoever has wings flies high and is no one's slave.

Aloha,
Mark