Your argument does not address my moral premises. You have no argument that can, until you produce a chicken that can adopt a moral code.
Whether they enjoy life or not is entirely irrelevant. If you wish to protect one, use your capacity as a moral entity to become the guardian of a chicken. We have a ready-to-use system in place for this--property. Buy a chicken, make it your property, defend it against all comers, and it is safe from me killing it, forever.