Abstract: A hydrolyzed proteinaceous milk solid is prepared from a heat treated skim milk liquor which contains denatured whey proteins as well as casein proteins. The solid is prepared by rapidly heating the skim milk liquor to a temperature above 170.degree. F. and adding acid to the heated skim milk liquor to adjust the pH of the liquor to a pH of about 4.7. The heated pH adjusted liquor is aged for a time period during which coagulation and agglomeration of whey and casein proteins, carbohydrates and ash takes place forming a plurality of coagulum suspended in the remaining whey liquid. The coagula is separated from the whey liquid, cooled, dewatered and dried. The resulting dry solid is treated with a caustic agent as, for instance, sodium hydroxide, in a solid phase reaction to yield the hydrolyzed proteinaceous milk solid.

Abstract: Pet food can be prepared from animal flesh by a process which includes separation of the flesh portions of the animal from it's bones during a deboning step. This yields a fibrous paste to which is added a quantity of hydrolyzed milk protein. The hydrolyzed milk protein is thoroughly mixed with the fibrous paste. A quantity of salt is then added to the mixture of the hydrolyzed protein and the fibrous paste, and a second mixing is utilized to thoroughly mix the salt into the mixture of the hydrolyzed milk protein and the fibrous paste. The final mixture is then placed into an appropriate mold of a desirable shape. The molded mixture is then quickly heated to 140.degree. F. to heat set the mixture into the mold, and to heat kill any enzymes or micro organisms present in the mixture.