This standard specifies the technical indicators, testing methods, inspection rules, labeling, packaging, transportation and storage requirements of compound acidifiers for feed. This standard applies to compound feeds made of phosphoric acid and organic acids (lactic acid, citric acid, fumaric acid, malic acid, tartaric acid, etc.), or several single organic acid regulators, which can increase the acidity of the compound feed (reduce the pH value), Or a homogeneous mixture to improve silage quality.