Mich. Comp. Laws § 287.533

Sec. 13. A person manufacturing or distributing commercial feed shall comply with all of the following: (a) The requirements in 21 CFR 558.6 for a veterinary feed directive drug as defined in 21 CFR 558.3. (b) The requirements in 21 CFR 589.1 to 589.2001 for prohibited mammalian protein. (c) The following requirements of manufacturing or distributing commercial feeds containing drugs: (i) The regulation prescribing good manufacturing practices for type B and type C medicated feeds in 21 CFR 225.1 to 225.202. (ii) The regulations prescribing good manufacturing practices for type A medicated articles in 21 CFR 226.1 to 226.115. (d) The requirements in 21 CFR part 507 for good manufacturing practices and preventive controls for animal food.