Roll of protein in Animal Growth.
All animals need to consume protein to supply the building blocks, called amino acids, that are used to build the proteins in muscle, membranes, enzymes and milk. Ruminant animals are different from non-ruminants in how they obtain amino acids. Non-ruminant animals derive all their amino acids directly from the protein in their feed. Ruminants derive amino acids from two sources: from the microbes that grow in the rumen and are then digested in the intestines, and from the feed protein that passes through the rumen and is then digested in the intestines (Fig. 1). This protein is commonly referred to as bypass protein.