I'm sure a lot of "do not feed" foods are subjective, while others are pretty straightforward. If you aren't comfortable feeding something, don't feed it. I know my parents' chickens have been in my mom's asparagus bed (she was not thrilled, let me tell you!), but they were fine. Lol. Migrating birds eat uncooked rice all the time, wild birds eat every part of the apple, etc. It's all about your own personal level of paranoia. Haha! I'll look into the asparagus thing more though. I'm curious now as well.