Choline Chloride (often classified as vitamin B₄) is an important member of the B‑vitamin complex. As an essential precursor for the synthesis of phospholipids, acetylcholine, and betaine, it performs critical physiological functions in animals, including promoting fat metabolism (preventing fatty liver syndrome), participating in methyl transfer (sparing methionine), maintaining nerve signal transmission, and supporting cell membrane structure. Feed‑grade products are primarily available as 50% or 60% powder adsorbed on plant carriers, or as 70% or 75% aqueous liquid solutions (conforming to GB/T 10818 standard). The powder form is convenient for compound feed processing, while the liquid form is more commonly used in premixes and liquid feeds. Deficiency in poultry leads to fatty liver, reduced egg production, and increased cracked egg rate; in pigs, it manifests as growth retardation, joint deformities, and lactation disorders in sows. Consequently, choline chloride is one of the most widely used basic additives in livestock and poultry feed. However, due to its strong hygroscopicity, it should be added separately at the final stage of feed production, and prolonged mixing with other vitamin premixes should be avoided to prevent potency loss.