Effect of adding cornzyme on fermentation quality and carbohydrate contents of napiergrass silages.

The aim of the experiment was to evaluate the effects of adding cornzyme on the fermentation qualities and carbohydrate contents of napiergrass silages.There was the control and four treatments of different cornzyme addition ratios as follows:(1) E1: cornzyme addition at 0.5 mL·kg-1,(2) E2: at 1.0 mL·kg-1,(3) E3: at 1.5 mL·kg-1,(4) E4:at 2.0 mL·kg-1 based on fresh weight of napiergrass.The results showed that all treatments had good fermentation quality with low pH value(4.28-3.76) and NH3-N/total N ratio,none or only small amounts of propionic acid and butyric acid,high ratio of lactic acid/acetic acid(2.94-13.46),and lactic acid content(45.00-95.41 g·kg-1 DM).Cornzyme addition significantly increased the ratio of lactic acid/acetic acid and the contents of lactic acid and water soluble carbohydrate(P0.05);and significantly decreased the pH values and the contents of acetic acid and total volatile fatty acids in comparison with the control(P0.05).The contents of neutral detergent fibre(NDF) and acid detergent fibre(ADF) tended to decrease in silages with cornzyme addition.When increasing the adding rates of cornzyme,the fermentation quality and water soluble carbohydrate content were further increased,however,NDF and ADF decreased.