Potential of the Locally Produced Lactobacillus Inoculants in Ensiling Guinea Grass Forage

Lactic acid bacteria (LAB) inoculants are employed to accelerate forage ensiling ensuring silage quality. Such inoculants are not produced locally and are restricted from importation in Sri Lanka. This study evaluates the potential of locally produced, freeze-dried LAB inoculants containing Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus oris, on the ensiling of guinea grass forage. Two experiments were conducted, each according to complete randomized design. Guinea grass, harvested at the 10 % flowering stage, was chopped (10 mm), inoculated with freeze-dried LAB (10⁶ CFU/g fresh fodder) and ensiled in laboratory silos. Guinea grass without inoculant served as a control. The silos were opened at 2 weeks and 52 weeks post-ensiling in the first and second experiment, respectively. Ensiled forage was assessed for pH and lactic acid content. Additionally, forage ensiled for 52 weeks was analyzed for organic matter digestibility (OMD) and metabolizable energy content (ME). Guinea grass ensiled with Lactobacillus exhibited significantly (P<0.05) higher lactic acid content and lower pH values as early as 2 weeks. At 52 weeks, guinea grass inoculated with L. plantarum and L. rhamnosus recorded exceptionally (P<0.05) low and high lactic acid content, respectively. Nevertheless, at 52 weeks guinea grass ensiled with, both L. rhamnosus and L. oris recorded significantly lower (P<0.05) pH values compared to those inoculated with L. palmensis. Inoculation of guinea grass with Lactobacillus significantly (P<0.05) increased the OMD and ME contents of silage. This study concluded that locally produced, freeze-dried inoculants with L. plantarum, L. rhamnosus, and L. oris can enhance ensiling of guinea grass.