Production of Lactobacillus Inoculants and Their Influence on Ensiling Forage Maize

Purpose: Lactic acid bacteria inoculants used to enhance forage ensiling. They are neither imported nor produced in Sri Lanka. The present research produced freeze-dried Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus oris inoculants, and assessed their influence on forage maize ensiling.
Research Method: Lactobacillus mother cultures were prepared from isolates from maize, sorghum, and Guinea grass silage using MRS broth (37⁰C, 18 h). These were further incubated in 10% skim milk broth (37⁰C, 72 h) to study growth kinetics. Skim milk broth (10%) was selected as the lyophilization medium. Pelleted cultures (10 mL) were resuspended in lyophilization medium (30 mL) and freeze-dried inoculants were produced from suspensions (0.5 mL). Forage maize was inoculated with these inoculants at 106 CFU/g fresh forage, and their effect on ensiling was analyzed.
Findings: In growth kinetics study, all Lactobacillus species exceeded 10⁹ CFU/mL population by 24 hours and reduced the pH to a range of 3.92–4.11, by 72 h. The influence of inoculation of Lactobacillus species was significant (P < 0.05) on silage pH. Significantly (P < 0.05) low pH was recorded when forage maize was inoculated with L. oris and L. rhamnosus at 2 and 52 weeks, respectively. An increasing trend in organic matter digestibility and metabolizable energy was evident with inoculation of L. rhamnosus and L. oris.
Originality/ Value: Locally produced freeze-dried L. rhamnosus and L. oris can effectively enhance the ensiling of forage maize, offering a solution for the unavailability inoculants for silage production in Sri Lanka.