Valine (Val) is an essential amino acid for pigs. It is also a branched-chain amino acid and has important biological functions. When the dietary protein level is reduced by more than 3%, the addition of valine can significantly improve the performance of pigs. An in-depth understanding of the structure and physiological functions of valine and determining the amount of valine required by pigs at different stages are of great significance to the nutritional research and production of pigs.
Like lysine, threonine, methionine and tryptophan, valine is an indispensable nutrient for pigs. Animals cannot synthesize valine, and must get enough valine from the diet to meet their needs. In addition to being used for protein synthesis, valine is essential for animal growth and reproduction. Valine can oxidize and supply energy during special physiological periods, regulate the protein turnover of skeletal muscle, improve the lactation performance of sows, and affect the immune response of pigs.
When the brain needs energy, even if it is rich in glucose, valine will be preferentially catabolized for energy. After the valine in the diet is digested and absorbed by the animal, although it can be directly catabolized in the liver, it is mainly oxidized and degraded in the muscle tissue. Valine is a sugar-generating amino acid. After entering the tricarboxylic acid cycle, it is metabolized according to the glucose pathway, and finally realizes the mutual transformation of the three major nutrients in the body. Valine is of great significance for promoting the development of sows' mammary glands, improving lactation performance, and increasing the weight of piglets at weaning.