Hyacinth bean

[Silverduck]

In the recent issue of Backyard Poultry, it had a hyacinth bean vine growing over a chicken run, I would love to plant something like this in the spring for shade. Does anyone know if chickens will eat it, or if it is safe. I know the beans are poison if not boiled twice. I planted pole beans one year but, the chickens ate them so it didn't make a good shade.

 

[ChickenCanoe]

I start vines about a foot away from the pen and give them something like string or slats to grow up a couple feet before I train them toward the pen.
I doubt if they would get enough of anything to be harmful.
I see my birds eat lots of things people have said were harmful but with no ill effects. If these things made up the entire diet that would be different.