A poultry and swine pulverizing or grinding apparatus comprises an enclosed housing having an inlet end and an outlet end. A grinding drum is rotatably mounted within the enclosed housing and provided with raised cutting teeth extending in a helical orientation along the longitudinal length of the grinding drum. A carcass retention element is positioned adjacent the length of the grinding drum and cooperates therewith to facilitate pulverizing or grinding of animal carcasses by the grinding drum into small size particles which exit the housing through the outlet end. The grinding drum of the apparatus is motivated by an operatively connected motor. Also described is an automated system for preparing animal carcasses for lactic acid fermentation and/or further processing utilizing the aforesaid grinding apparatus.