Screening a Lactobacillus plantarum strain for good adaption in alfalfa ensiling and demonstrating its improvement of alfalfa silage quality.

ABSTRACT

AIM: To screen a lactic acid bacteria (LAB) strain for good adaption in alfalfa ensiling and to evaluate its effects on alfalfa ensiling. METHODS AND RESULTS: Lactobacillus plantarum (LP) strain ZZU203 was selected due to its superior ability to acidify structural carbohydrate metabolite and alfalfa powder. Alfalfa was ensiled with LP FG1 (from a commercial inoculant), LP ZZU203, or a no-additive control (CK) for 60 d. The two silages with LP additives significantly (P < 0·05) increased lactic acid (LA) and acetic acid (AA) concentrations compared to CK silage. The pH, ammonia nitrogen (NH3 -N) and cellulose concentrations, and the numbers of bacilli, coliform, aerobic bacteria and Clostridium decreased significantly (P < 0·05). The dry matter, LA, AA and water-soluble carbohydrate concentrations of ZZU203 silage were significantly (P < 0·05) higher, whereas the NH3 -N and the neutral detergent fibre concentrations, and the aerobic bacterial and Clostridium counts were significantly (P < 0·05) lower than in FG1 silage. CONCLUSION: ZZU203 obtained by the screening method of this study can improve the quality of alfalfa silage. SIGNIFICANCE AND IMPACT OF THE STUDY The screening method designed for alfalfa silage conditions can effectively screen out LAB with potential application value in alfalfa silage.