The effects of the L. plantarum strain RC1.4 starter culture with or without sucrose addition on fermentation efficacy, microbial content, and aerobic stability indicators of alfalfa silage

Abstract

To develop the approach for efficient alfalfa silage fermentation, L. plantarum strain RC1.4 (LP-RC1.4) was used as starter culture with or without sucrose. Trial groups consisted of ten repetitions for each treatment including (1) control, with added sterile water (10 mL); (2) LP, silages treated with LP-RC1.4 alone (106 cfu g$^{-1}$ FM); (3) LP-S1, silages treated with LP-RC1.4 (10$^{6}$ cfu g$^{-1}$ FM) plus sucrose at 10 g/kg fresh matter; (4) LP-S$_{2}$, silages treated with LP-RC1.4 (106 cfu g-1 FM) plus sucrose at 20 g kg$^{-1}$ fresh matter. Inoculation improved the quality of the silaging demonstrating a lower decrease of silage dry matter (DM) in comparison to the control silage. The CO2 production was also lower in the inoculated silages. The addition of sucrose improved microbiological and biochemical parameters of the resulting alfalfa silage, simultaneously with the increased number of lactobacilli, raised the content of water-soluble carbohydrates, while the number of yeasts and molds decreased. It was concluded that LP-RC1.4 inoculation should be supported with sucrose to insure domination of LAB fermentation and enhance of the silage quality of alfalfa.