Meat byproduct. Any part capable of use as human food, other than meat, which has been derived from one or more cattle, sheep, swine, or goats. This term, as applied to products of equines, shall have a meaning comparable to that provided in this paragraph with respect to cattle, sheep, swine, and goats.
9 CFR § 301.2
As used in this subchapter, unless otherwise required by the context, the following terms shall be construed, respectively, to mean: