Hello Bob,
I am spending some time with this song and I too have found this thread intriguing.
It is a song of depth - again, whether "invented" or a more aged folk-song, I think it draws on folk-song traditions and on folk traditions in general. Deep waters as you say.
We each have our personal response and a good piece of literature (any art) will do that. There is something in it for everyone.
AND YET... Knowledge, understanding of the cultural background, of similar traditions... These can enrich our understanding of the song, and also prevent misunderstanding. Such is my view of literary analysis. I like to try and figure out what is in the song and not just what is in my mind.
Having thought about it some more after writing, I had the following further insights...
The song does end with a message, and even though it is partly ironic, with the wind laughing itself away in the background, it is also true: Whoever has wings can soar up, and be nobody's slave. But a calf is always subject to binding and slaughtering. Does that blame the calf? That would be callous indeed, and it is the farmer's voice who bluntly says that. But at the same time - the song is saying, we need to strive to be free, to be a swallow and not a calf. This is not "blame" but a message, a truth to be heeded. These paradoxes are part of life and that is why the song is enigmatic about it, as a good song should be.
A somewhat similar sentiment is expressed in the song "El Condor Pasa" (I don't know if Paul Simon's lyrics are based on a folk song or not, I know the music is based on folk songs): "I'd rather be a sparrow than a snail / Yes I would / If I only could / etc. and, "A man gets tied up to the ground / he gives the world / it's saddest sound".
In probing the song (Dona Dona), it is important not to be mislead by the English translation. The English says, "but whoever treasures freedom / Like the swallow has learned to fly". The original Yiddish does not say that - it only says, "Whoever has wings flies upwards / (and) is nobody's slave." Nothing about treasuring, nothing about learning... It's just a plain fact, but a fact that needs to be noted. The translation to English turns the song from a philosophical statement, albeit an important and inspiring one, to a "didactic" and more moralistic statement.
And re the winds laughing, I am reminded also of a Hebrew expression, "the laughter of fate", which I imagine exists in some form of another in many languages and cultures.