Can you feed chickens warrigal greens?

[chookpalace]

Here's a question for Australians or New Zealanders: Can you feed chickens a native plant called Warrigal greens? If anyone else wants to hazard a guess, it's a tough succulent-like groundcover plant which people can eat in place of spinach. I cook with it often and I have heaps of it. I think they would like it, but am a bit scared to try as i know it has oxalic acid in it (in amounts not problematic to people) (as does spinach and they can eat that), I'm just concerned about how to know if a) chickens can process it OK and b) how do I know how much is ok or can I give it to them unrestricted? Any clues?