Producing a colostrum-product comprises: (a) defrosting a frozen raw colostrum (1) and heating to a temperature of less than 10[deg] C, preferably 4-10[deg] C (b) adjusting a fat (4) content of less than 0.5 mass%, preferably less than 0.2 by partition method (c) precipitating casein by an addition of a protease in the form of rennet (chymosin enzyme) and (d) subjecting the obtained liquid (3) to at least one sterile filtration stage. An independent claim is included for an apparatus comprising means for defrosting and/or mechanical crushing of frozen raw colostrum, an agent for separating fat, and an agent for precipitating and sterile filtering casein by rennet enzyme. ACTIVITY : Anabolic. MECHANISM OF ACTION : None given.