Where are non-degradable proteins primarily absorbed in dairy cattle?

Non-degradable proteins, also known as bypass proteins, are primarily absorbed in the small intestine of dairy cattle. This is because the small intestine is specifically structured for the absorption of amino acids and small peptides derived from the breakdown of proteins.

When non-degradable proteins enter the digestive system, they bypass the rumen, where microbial fermentation occurs. Instead, these proteins travel down to the small intestine, where they are broken down by enzymes into absorbable forms. The amino acids and peptides are then absorbed through the intestinal walls and into the bloodstream, providing essential nutrients for the animal.

While protein digestion begins in the stomach with the action of gastric enzymes, the actual absorption of the final breakdown products predominantly takes place in the small intestine, making it the key site for non-degradable protein absorption. The large intestine and rumen do not play significant roles in this process for non-degradable proteins; the rumen is primarily involved in fermenting degradable proteins and facilitating microbial protein synthesis.