Chlortetracycline 15%-CTC 15% is the name given to an antibiotic feed-grade containing 15% chlortetracycline, a broad-spectrum tetracycline antibiotic used in veterinary medicine. Chlortetracycline is of the tetracycline-class antibiotic in which the mechanism of action is through the inhibition of bacterial protein synthesis. The formulation is usually in animal feed; the 15% refers to the percentage concentration of active ingredient in the final product, which is thereafter mixed into the animal feeds at particular concentrations. It enhances the health, feed conversion, and growth rates of animals, though its application needs to be carefully controlled to prevent antimicrobial resistance and ensure food safety. Chlortetracycline 15%-CTC 15% is the most widely used broad-spectrum antibiotic used in animal livestock or poultry production, targeting the treatment and prevention of various bacterial infections, such as respiratory diseases and intestinal infections.