Choline,physiological functions,deficiency,toxonosis,GRECO...

Choline (trimethyl ethanolamine) is a kind of colorless, viscous and strongly alkaline liquid with slight savour of fish. Choline reacts on acids to form stable crystalline salts, which have a strong hygroscopic nature and sends forth an offensive odour of amine after absorbing CO2. Choline dissolves in water, formaldehyde and ethanol while has a bad solubility in acetone and chloroform. It is insoluble in petroleum ether, benzene and has a good thermal stability.

The most commonly used form of choline is choline chloride (70% aqueous solution), an additive for commercial application.

Characteristics: Colorless, transparent viscous liquid with slight nasty smell. Dissolves in methanol and ethanol, badly dissolves in ethylether, chloroform and benzene. Having hygroscopic nature, absorbing CO2 and giving out odor of amine.

Item index:
Choline content ≥ 70%
Alkalinityacidity (pH value): 6.5-8.0
Ethylene glycol ≤ 0.5%
Chloroethanol (as Cl- ) ≤ 0.2%
Trimethylamine: up to grade
Residue on Ignition: ≤0.2%
Heavy metals (as Pb) ≤0.002%

Choline chloride liquid has strong corrosivity and must be stored in special reservoir and additional equipment. Choline chloride has also destructive effect on other vitamins, especially when accompanied by metallic elements, will do damage to vitamin A, vitamin D, vitamin E and vitamin K, etc. Thus, it suggests that choline chloride not be mixed with vitamin premix but can be added into concentrated feed and complete formula feed directly.

Choline differs from other vitamins in the B group. It does not function as catalyst but an essential component of animal organism.

① It is a key constituent of lecithin which plays an important role in maintaining cell structures and functions.
② It accelerates the transmission of hepatic fat as the form of lecithin or improve the oxidation of fatty acid in the liver.
③ It prevents fatty liver.
④ It is a precursor to acetylcholine in impulse transmission of all nerves.
⑤ It acts as donor of methyl group in the reaction of transmethylation.

Choline deficiency often occurs in swine and poultry with symptoms like tardy growth and soakage of hepatic fat, fatty liver, cartilage disease, organic haemorrhage and hypertension; also short shinbones and lower eggs production for poultry.

The basic choline intake for poultry is ranging from 500mg to 2000mg in 1kg feed. The maximum intake quantity for chooks may be twice than its basic range while pigs may take more. However, over forced feeding may cause sialorrhea, tremor, spasm, eclampsia and anaesthetization of breathing and other adverse effects.