Will chickens eat buttercup bur?

[fowlerclaire]

I have just discovered we have a TON of buttercup bur growing on our new property and I have missed my opportunity this spring to take care of it (it's already going to seed). I have some chicks and will be getting more pullets soon. I had hoped to let them do some free ranging, but now I"m worried about how the buttercup may affect them! It is poisonous to livestock....SO my questions are

Will the chickens eat it?
If they do, is it poisonous to them like it is to livestock?

Any and all advice or info about this noxious weed and it's affects on animals would be appreciated!

Thanks!