Betaine was found in Europe in the early 1860 s, a substance is extracted from beet root, it is the trimethyl glycine derivatives, the formula for C5H11NO2, relative molecular weight of 117.15, betaine is yellow or white crystal, taste sweet, slightly bitter, nature is stable under 200 ℃, soluble in water and alcohol, organic solvents, Decompose to trimethylamine in strong alkali. As amphoteric quaternary ammonium alkaloid, its molecular structure is characterized by neutral internal charge and three active methyl groups. It can be an essential nutrient (or additive) under certain conditions.

Animals can synthesize betaine to meet their own needs. Betaine is synthesized by the well known oxidation of vitamin choline. The effect of feed additives in animal husbandry has been shown to save choline by adding pure betaine to feed. Betaine can also replace methionine, which is expensive, as a methyl donor. Therefore, adding betaine to feed can reduce the need for methionine and choline.

Betaine can be overfed when water is scarce, not as a methyl donor, but as a regulator of cellular hydration. In a state of heat stress, cells respond by aggregating inorganic ions, such as sodium, potassium, chlorine, and organic permeators like betaine. In this case, betaine is the most effective compound, since it has no negative effect of causing loss of protein stability. As an osmotic regulatory substance, betaine can protect the kidney from the harm of high concentration of electrolyte and urea, improve the function of macrophages, regulate the water balance in the intestinal tract, and prevent premature cell death in the state of water shortage.