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

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.