Digestion of protein in the reticulo-rumen

• Food proteins of plants and animal origin are hydrolyzed to polypeptides then to smaller peptides and amino acids by extracellular microbial proteases.
• The amino acids are degraded further by intracellular microbial deaminases to ammonia and organic acids, and CO2.
• The ammonia produced together with small peptides and amino acids is utilized by rumen micro-organisms to synthesize microbial proteins.
• NPN sources also readily degraded in the rumen to ammonia then to microbial protein.
• After this when the organisms are carried through to the abomasum and small intestine they will be digested by the proteolytic enzymes of the host and absorbed as amino acids.
• If the animal is supplied which excess nitrogen, there will be excess ammonia production which will be converted to urea is liver and animal has mechanism to remove excess urea by excreting it in the urine.