Fatty acids and glycerol are the end products of fat digestion. The lymph absorbs these products. The final products
of carbohydrate digestion are monosaccharides and VFAs (volatile fatty acids). The end products of protein digestion
are amino acids and peptides. They are all absorbed by the blood. Water and inorganic salts are also absorbed by the
blood. Digestion is complete after absorption has made the nutrients available for other parts to use.
In poultry, the gizzard secretes no enzymes; it only functions in grinding coarse food. Feed passes from the gizzard
into the duodenum, which is parallel to the pancreas in other species. This is where pancreatic juices are brought
into the mix. The juices contain amylolytic, lipolytic, and proteolytic enzymes. Liver bile is also secreted into the
duodenum to aid in the digestion of fats. The enzyme erepsin finishes digesting proteins for conversion into amino
acids. This happens in the small intestine. Some sugar-splitting enzymes further simplify starches. The villi of the
small intestine are the primary site of absorption.