In hopes of heading off positive drug tests for zilpaterol, the California Horse Racing Board (CHRB) is warning trainers of sweet feed products containing a molasses base produced by Purina at its Turlock, Calif., mill.

In an advisory issued March 22, the CHRB said it has concluded a number of such products contain zilpaterol, which is prohibited in racing. Zilpaterol is a beta-2 agonist used to promote weight gain in livestock. Association of Racing Commissioners International classifies zilpaterol as a Class 3 drug with a Category A penalty.

Originally published on BloodHorse.com.