In the present study, an amino acid mixture had been prepared from whole swine blood by acid hydrolysis, ion-exchange separation and adequate supplementation of L-Trp, L-Met, and L-Ile. The content of essential amino acid, chemical score and essential amino acid index of the product were 49.33, 63.77, and 92.38% respectively and its essential amino acid pattern was closely similar to casein or whole egg protein with sulfur-containing amino acid as its first limiting amino acid. In the rat growth experiment, its nutritional value had been proved to be comparable with casein and better than swine blood powder itself in terms of weight gain, PER, and NPR. Therefore, this amino acid mixture can be considered as an ideal food additive and nitrogen source for elemental diet and this is an important way in the utilization of swine blood.

An elemental diet, commercially named Elementalio, contains an amino acid mixture and many other essential nutrients. The amino acid mixture is prepared from hydrolysis of swine blood and supplemented with certain crystalline L-amino acid. The animal experiments suggest that it has a better nutritional effect than other domestic elemental diets in terms of body weight gain, nitrogen balance and correction of hypoproteinemia.