Betaine is called trimethylglycine or trimethylamine ethyl lactone,the molecular formula is C5H11NO2, the relative molecular weight is 117.15.Neutral in aqueous solution, white ribate or leaf crystal, melting point 293℃, can withstand the high temperature of less than 200℃, with strong oxidation resistance, moisture retention.It’s soluble in water、methanol and ethanol,insoluble in diethyl ether.It is easy to absorb moisture and deliquescent in the air at room temperature.There are two characteristics of molecular structure: the charge distribution in the molecule is neutral,it has three active methyl groups.

Betaine can significantly increase growth hormone (GH) and insulin-like growth factor ⅰ (IGF- ⅰ), which can promote protein deposition in tissues and improve lean meat rate of the carcass.  In addition, the addition of betaine increased the content of cyclic adenosine (CAMP) in liver and adenohypophysial gland,promoted gene transcription and catalyzed protein phosphorylation through activation of camp-dependent protein kinase, thus increasing energy mobilization and promoting protease secretion. Protein biosynthesis is carried out with mRNA as template, while RNA transcribed with DNA as template must be processed and modified, it is an important modification for methylation.

The research found that betaine can significantly increased the RNA content of breast muscle cells by 15.21% (P<0.05) and the RNA/DNA ratio by 19.13% (P<0.01) and the serum uric acid concentration decreased by 10.96% (P<0.05) with adding 1000mg/kg betaine to Avian broiler aged 29 to 49 days.It showed that betaine could enhance the nitrogen storage capacity of the body. Glycine and serine can form betaine through the phospholipid pathway and consume amino acid in the body. Adding betaine in feed dietary can not only save methionine dosage and increase the contents of carrier proteins such as choline and carnitine, but also produce lysine, glycine and serine metabolically.