# Amino acids for feed (lysine, methionine, threonine, tryptophan)

Upstream — fermentation & cell culture — Fermentation-produced lysine, methionine, threonine and tryptophan let feed formulators hit exact amino-acid targets in lower-protein rations, reducing nitrogen excretion.

Source: https://en.bioecon.ru/market/upstream/amino-acids-feed-additives/