Biological roles of tryptophan and its metabolism: Potential implications for pig feeding

Sanguinarine does not influence availability or metabolism of tryptophan in pigs

“…In agreement with previous studies, the present results provide further evidence that tryptophan deficiency in pigs exerts a specific depressive effect on voluntary feed intake, and consequently on growth performance (Henry et al, 1992;Le Floc'h and Seve, 2007). Supplementation of Sangrovit® had no influence on growth performance and feed intake in pigs fed diets adequate or deficient in tryptophan, indicating that sanguinarine does not affect tryptophan availability through a reduced bacterial decarboxylation in the intestine or an increase in appetite by modulation of the tryptophanserotonin pathway, as proposed earlier on the base of in vitro studies showing a nearly complete inhibition of the Laromatic amino acid decarboxylase of rat liver at concentration of 1000 μmol/L (Dršata et al, 1996).…”

Effects of surplus dietary L-tryptophan on stress, immunology, behavior, and nitrogen retention in endotoxemic pigs1

“…For instance, catabolism of the essential AA Trp is increased in infected piglets through activation of the enzyme indoleamine 2,3-dioxygenase (IDO; Melchior et al, 2003Melchior et al, , 2005. Therefore, during infiammation, Trp utilization is enhanced (Le Floc'h et al, 2008, 2009 and Trp is thought to be ratelimiting for proper immune system functionality (e.g., anti-inflammatory properties and production of acutephase proteins and antioxidants; Le Floc'h and Sève, 2007) and proper whole-body protein retention in slowgrowing pigs (Le Floc'h et al, 2004;Melchior et al, 2004). In addition, it has been shown (Koopmans et al, , 2006(Koopmans et al, , 2009) that a diet supplemented with 5 g of 241 free L-Trp/kg reduced the plasma concentrations of the catabolic stress-hormone, cortisol.…”

Digestible tryptophan levels for 30 to 60 kg pigs

“…According to Jansman et al (2010), the lysine concentration of the experimental diets and the immune system activation of pigs (Le Floc'h et al 2007;Trevisi et al, 2009) are among the factors that may explain the variation in estimates of pigs' digestible tryptophan requirements observed among studies. Confirming this proposition, Jansman et al (2010), Eder et al (2003) and Guzik et al (2005) found that the weight gain of pigs in the finishing phase was significantly influenced by the levels of tryptophan in the diet, with the best gain response obtained at 0.146 and 0.096% digestible tryptophan, which corresponded to the same relationship with digestible lysine (18%).…”

“…Tryptophan is the fourth limiting amino acid after lysine, methionine and threonine. When the level of tryptophan in the diet is limiting compared with other essential amino acids, protein synthesis, body weight gain and feed efficiency are adversely affected (Le Floc'h & Seve, 2007;Jansman, 2010).…”