Wilfred [[Oh god, and now they are bowdlerizing the folksongs!
In the original the poor calf is slaughtered without anaesthetization; that is the meaning of schekhtn.]]

As I've learned the song (including the way Joan Baez sings it), the line is not
"Calves are easily bound FOR slaughter"
But
"Calves are easily bound AND slaughtered."

English doesn't have a verb comparable to "schekthn" and the closest translation that would scan with the tune seems to be just to use the word "slaughtered" (which does not imply anesthetization).

But this is a digression from the question of what "Dona Dona" means.