- Amino acids are involved in various important metabolic pathways beyond growth, including modulating the functioning of the body’s immune system.
- During a condition of sub-clinical disease, increased dietary supply of functional amino acids (i.e. methionine, tryptophan, threonine, arginine, glutamine, and glycine) ameliorates the negative effect of growth reduction associated with immune challenge.
- Based on the available literature, increasing ideal ratios of some functional amino acids – such as the standardized ileal digestibles methionine+cystine:lysine (+ 6%-points), tryptophan:lysine (+ 3%-points), and threonine:lysine (+ 5%-points) – relative to the ratios applied for their healthy counterparts can enhance immune status and optimize growth performance of pigs challenged by sub-clinical disease.
- In pigs with subclinical infections of the gut, increased dietary supply of threonine, arginine, glutamine, and glycine may help enhance immune status and gut integrity.
- Further research is needed to assess the interaction or synergistic effects of these functional amino acids on an animal’s immune function.