Lysine is, together with 20 other amino acids, a fundamental building block of all proteins and is therefore an important nutrient for maintenance, growth and (re)production. Lysine is also an essential amino acid. This means that it cannot be produced by the body and must therefore be taken up via the feed.

Intestinal digestible lysine is made available through the microbial protein and resistant (feed) protein. For optimal milk production, lysine and methionine appear to be the first-limiting amino acids. The content of intestinal digestible lysine and methionine in feedstuffs is therefore important. These contents can be shown on the feed value report from Eurofins Agro and are calculated in the same way as the intestinal digestible protein fraction.