THREONINE

threonine is usually the second limiting amino acid after lysine for pigs and the third one after sulphur amino acids (methionine + cysteine) and lysine for poultry. As lysine, threonine is an indispensable amino acid for body protein deposition and growth. Thus, deficiency in threonine affects the utilization of dietary lysine and consequently animal growth. Besides its utilization for protein synthesis, threonine is involved in other biological functions such as gut integrity and immunity.

Besides its utilization for protein synthesis, threonine is involved in other biological functions such as gut integrity and immunity. Thus, a deficiency in threonine leads also to disorders in the digestive physiology which can, in turn, increase the frequency of digestive problems. As a consequence, threonine requirement varies depending on the relative importance of these different functions. It is therefore important to determine the threonine requirement which corresponds to each physiological stage to improve the balance and efficiency of feeds.

Additionally, endogenous losses are very rich in threonine. For instance, threonine to lysine (Thr:Lys) ratio in endogenous losses have been measured to be 120% in pig endogenous losses and in poultry, 174% in ileal juice and 132% in excreta. This specific threonine trait linked to its metabolic functions, underlines the importance of using standardized (or true) digestibility (SID in pigs and TD in poultry) because this system takes into account endogenous losses.

threonine.jpg

Search