STUDIES REGARDING INFLUENCE OF DIFFERENT STRAW-BASED RATION TYPES ON FERMENTATION AND PRODUCTION OF VOLATILE FATTY-ACIDS (VFA) IN RUMEN OF LACTATING COWS .2. RUMENAL FERMENTATION PROCESSES AND MILK YIELD CRITERIA AFTER USING A LOW-FIBER STRAW PELLET BATCH AS BASAL RATION COMPONENT AND A FULLY PELLETED STRAW-BASED RATION