This standard specifies high-performance liquid chromatography and liquid chromatography-tandem mass spectrometry for the determination of oxytetracycline, tetracycline, chlortetracycline, and doxycycline in feed. Liquid chromatography-tandem mass spectrometry is the confirmation method. This standard is applicable to the determination of oxytetracycline, tetracycline, chlortetracycline and doxycycline in compound feeds, concentrated feeds, additive premixed feeds and concentrate supplements.