Welcome to BYC. I think the chickens would love them. From what I have read, grubs are high in protein. There is a lot of information about raising and feeding Black Shoulder Fly grubs to supplement their feed.
Yes, chickens love them-- MY problem is that I can't stand to pick them up, nasty things! Then there's my 4-year-old, who thinks the grubs are "so sweet and so cute!" and has no problem picking them up, but refuses to feed them to the chickens.