Author: Site Editor Publish Time: 2021-10-21 Origin: Site
Threonine, the second or third limiting amino acid of pigs and the third or fourth limiting amino acid of poultry, is an essential amino acid for livestock and poultry to maintain growth.The metabolism of threonine is different from other amino acids in the body. Threonine is the only amino acid that is transformed into other substances by threonine dehydratase (TDH), threonine dehydrogenase (TDG) and aldolase catalyzed by dehydrogenase and transaminase.It is metabolized to glycine and acetaldehyde by aldose, amino propionic acid, glycine and acetyl CoA by TDG, and propionic acid and gamma-aminobutyric acid by TDH.Acetyl CoA can enter the tricarboxylic acid cycle and be completely oxidized to provide energy for the body.It can also be used as a prerequisite for synthesis of fatty acids and ketone bodies.Glycine can function as a non-essential amino acid to synthesize proteins deposited in the body.
In addition to balancing amino acids in the body, threonine is a carbon unit source involved in the biosynthesis of purines and pyrimidines, as well as s-adenosine methionine, and can be used as a donor for the methylation of various compounds.
Nutritional and Physiological Functions of Threonine and its Application in Livestock and Poultry Diets Threonine is an essential amino acid required by animals.Threonine can be converted into serine, glycine, butanyl CoA, succinyl CoA and so on.Adding proper amount of threonine in the diet can meet the needs of essential amino acids of livestock and poultry, promote growth and feed conversion, reduce the growth inhibition caused by excessive tryptophan or methionine, and eliminate the decrease of body weight gain caused by excessive lysine.Addition of threonine can not only balance amino acids, but also promote protein synthesis in the body.Enhancing the immune function of livestock and poultry Threonine is the main component of immunoglobulin, lack of threonine will inhibit the production of immunoglobulin, and then affect the immune function, adding threonine can increase the content of immunoglobulin in animals, enhance immunity, reduce mortality.
Different levels of methionine affect the ratio of thymus to body weight, while different levels of threonine affect the ratio of spleen to body weight, and the two amino acids significantly affect the content of IgG in blood and half hemolysis value, indicating that these two amino acids are related to immune function.
Effects of Threonine on immune Function of Pigs Threonine has important effects on immune function of pigs, especially humoral immunity.Threonine can affect the synthesis of immunoglobulin and regulate the immune response.Adding proper amount of Threonine can improve the immune function of pigs.Threonine content in colostrum and regular milk immunoglobulin amino acid composition is the highest, which is important for piglets.Piglets get immune protection through colostrum, which contains a large amount of immunoglobulin, immunoactive cells, non-antibody protective proteins and other immunoactive substances, which is of great significance to prevent external pathogens from entering piglets.