The Effects of Homofermentative Lactobacillus on Ensiling Characteristics and in Vitro Digestibility of Low-moisture Alfalfa Silage

The objective of this study was to determine the effect of homofermentative lactobacillus on the fermentation quality and in vitro digestibility of low-moisture alfalfa (Medicago sativa) silage. Single factor treatments were designed with Control (C), and Lactobacillus coryniformis (LCO), Lactobacillus casei (LCA), Lactobacillus plantarum (LP) and Lactobacillus pentose (LPE) addition. Alfalfa was harvested at the early flowering stage and dried in the field (5 h) until the dry matter content was about 50%, then the silages were prepared. After 60 days ensiling, the silage fermentation quality was determined, their nutritional value was evaluated based on Cornell net carbohydrate and protein system (CNCPS) and digestibility was evaluated by in vitro gas production method. The results showed that the pH value of LPE group was significantly lower than that of other groups (P<0. 05). Compared with the Control, the content of NH3-N in LCO, LCA and LPE groups decreased (P<0. 05); and the content of non-protein nitrogen in all lactobacillus groups decreased (P<0. 05); the content of rapid degradation protein and intermediately degraclable protein in LP and LPE groups increased (P<0. 05) while the contents of rapidly degradable carbohydrates in LP and LCA groups decreased (P<0. 05). In in vitro fermentation test, the gas production, dry matter digestibility and neutral detergent fiber digestibility of silage in LPE group were higher than those of control (P < 0. 05). Therefore, adding L. pentose to low moisture alfalfa silage (with 50% dry matter content) could improve silage fermentation quality, nutritional value and in vitro digestibility.