Hi People,
I'm not sure I'm following the delicate insider communication, but a few comments nevertheless...
Wee Little Drummer of the past: When I was little, I found this song hard, because of the harsh imagery, and because of the farmer's crassness/cruelty. At the same time, I listened and took it in, feeling intuitively that people, peoples who are in cruel situations, and undergoing extreme suffering, sometimes DO derive comfort from songs and stories that tell such tales and deal with such situations.
Specifically, as I said before, I hear the farmer's voice as distinctly different from the voice of the song, the farmer's voice is presented and mocked - although of course it is very, very real - the self justification, the gloating at his own better situation.

I think the original Yiddish makes this much much clearer, so I will try to translate:

On a wagon there lies a little calf, lies bound with a strap.
High in the sky flies a swallow, joyfully circling back and forth.
The wind laughs in the cornfield, laughs and laughs and laughs,
It laughs for a whole day, and half of the night.
Dona dona...
"Cry, you little calf", says the farmer, "Whoever told you to be a calf?
You could have been a bird, you could have been a swallow..."
{Hah! (my insertion)}
The wind laughs in the cornfield, laughs and laughs and laughs,
It laughs for a whole day, and half of the night.
Dona dona...
Poor calves - one binds them, carries them off and slaughters them.
Whoever has wings flies high up, and is a slave to no-one.
The wind laughs in the cornfield, laughs and laughs and laughs,
It laughs for a whole day, and half of the night.
Dona dona...

The farmer addresses the calf directly. His, "cry, little calf..." can be rephrased as "go ahead and cry", or "cry all you want". It is not a command but an expression taken directly from a culture that says "crying isn't going to help you".

Because in the end, the calf, the swallow, the farmer, the wind and the narrator - all are the voices of the song. Doesn't Jewish culture, like other folk traditions, have this voice inside it: "Don't complain, stop whining, it won't help". And at the same time - poor calf, he doesn't have wings, what can a poor calf do? Such is the fate of the calf. Should we cry, like the calf? Laugh, like the wind, because we can't change fate? Or soar like the swallow, in spirit if not in body, even when we are bound and led to slaughter - always looking upwards at the sky?

Next week is Holocaust Day in Israel. This is why I have been looking into this song. And the more I look, the more I feel it is such a deep, ironic rendition of the spirit of an oppressed people - of all opressed peoples, but in this case, tinged with Jewish irony and humor - such as, the wind laughs all day through, but half the night... Precisely half the night, right? To joke and tell tales even in the face of harsh fate, that is strengh of spirit... Maybe that is the soaring up of the swallow?