Does your mom know you want to feed the asparagus to your chickens? I can't keep my chickens out of the asparagus bed. I'm fencing the bed off tomorrow!
According to Buff Hooligan's Treat Chart, yes, it is okay to feed but it is not a "favorite". Raw or cooked...either one is okay. My chickens always loved the "seed pod" part that forms in the late summer/fall. They look like hard green berries.