Sec. 15. "Capable of use as human food" means any livestock or poultry carcass or part or product of a livestock or poultry carcass, unless the carcass or part or product of the carcass is:
(1) denatured or identified as not for human food as required by rules adopted by the board to deter its use as human food; or
(2) naturally inedible by humans.