The present invention relates to a kind of methods,It is digestible for generating,Keratin material partly hydrolyzes,Preferably from feather,Hair,Wool,Hoof or nail,The following steps are included:(1)Hydrolysis of keratin material under the conditions of existing for the water,Heat is being used in hydrolysis and in a pressure between about 2 bars and about 15 bars,With(2)Keratin material of the drying and grinding resultant force hydrolysis in an air turbulence is ground in about atmospheric pressure simultaneously,So that the drops in pepsin and/or ileal digestibility is less than 10%,And/or pepsin and ileal digestibility are kept above 75% and 80% respectively,As the keratin material for using a dry mash Beckman Kurt particle size analyzer wherein to synthesize with laser diffraction measurement at least partly includes insoluble material,Wherein the average particle size of dry product makes air turbulence grinding machine be measured as the d50 in volume fraction at about 20 microns and about 0.D90 is below about 1 millimeter between 7 millimeters.
