The Effectr Of Lactic Acid Bacteria And Rice Bran On Dynamic Change Of Rice Straw Silage Fermentation

The effects of adding lactic acid bacteria (LAB) and rice bran (RB) on the fermentation quality in the process of ensilage were studied, the experiment material was rice straw, and the test was based on single factor design. The experiment was consisted of three parts:one was adding lactic acid bacteria (LAB) only and the adding level was 0.005, 0.01,0.02 g/kg (based on fresh weight), another was adding rice bran (RB) only, the adding level was 50,100,200 g/kg (based on fresh weight), the last was adding LAB and RB at the same time, the adding level was (0.005+50), (0.01+100), (0.02+200) g/kg (based on fresh weight), each level was tested three times. The chopped rice straw was placed into vacuum-packed polyethylene bags and stored at room temperature. All treatments were opened after 1,2,3,5,7,10,14,24 and 35 days of ensiling and the fermentation quality was analyzed.The results showed that:(1) In LAB group, the pH value and the percentage of NH3-N in total nitrogen (NH3-N/TN) declined, with the increase quantity of adding LAB the value of above were decreased. The content of organic acids of rice straw silages were increased, especially the content of lactic acid. The fermentation quality was improved to some extents, but according to the pH value of excellent silage, the silages of this experiment was not meet the standard. Compared the silages of the LAB group with material, the content of crude protein (CP) and acid detergent fibre (ADF) increased (P<0.05), the effects on the content of dry matter (DM), water soluble carbohydrate (WSC) and neutral detergent fibre (NDF) were not significant (P>0.05). (2) In RB group, the pH value, NH3-N/total N, the contents of acetic acid, propnic acid and butyric acid were evidently declined (P<0.05), the contents of lactic acid increased (P<0.05). Besides, the contents of CP, WSC were increased (P<0.05), the contents of NDF, ADF were decreased. (3) Adding the lactic acid bacteria and rice bran at the same time, the lactic acid fermentation was improved, the contents of lactic acid were increased (P<0.05), the pH value and NH3-N/total N were significantly declined (P<0.05), meanwhile, the contents of propnic acid and butyric acid were declined.According to this test, the additive of lactic acid bacteria, rice bran could, to different extents, improved the fermentation quality of rice straw silages, in which pH value, NH3-N/total N and butyric acid decreased, lactic acid increased. Besides, the additive also improved nutritive value of rice straw silages, with the increase of CP and WSC contents, the decline of NDF and ADF. From the whole perspective, the descendent of this experiment was rice bran> lactic acid bacteria+rice bran>lactic acid bacteria.