If it's green and cabbage looking, my buns will eat it, no matter what it is called. They also love brocolli, especially the stalks.
If yours have never had it before, I would introduce it gradually, 1 leaf each to start with and see how it goes.. then increase if all is well.
Wish I could find a cheap outlet for curly kale, cos I love it, and it is always too expensive :shock: