Choline (commonly in the form of choline chloride) is referred to as vitamin B-complex. It is essential in building and maintaining cell structures as well as in fat metabolism. It is used by most animals as a precursor of acetylcholine, which influences the transmission of impulses from nerves to muscles. It is also used as a source of methyl groups. Therefore, choline chloride is widely used as feed additive at home and abroad. It will stimulate the animal or poultry抯 growth, put on their weight rapidly, boost up the body抯 immunity function. It has prominence effects on improving the quality and quantity of eggs and meat. On the contrary, shortage of choline may cause liver diseases, retarded growth, perosis, reduced egg-laying rate and increased mortality.