Effect of Harvest Maturity and Lactiplantibacillus plantarum Inoculant on Dynamics of Fermentation Characteristics and Bacterial and Fungal Community of Triticale Silage

(1) Background: Suitable harvest maturity stage selection and microbial inoculation during anaerobic fermentation are effective strategies for improving the quality of triticale (× Triticosecale ) silage for ruminant nutrition. (2) Methods: In the present study, the fermentation characteristics, microbial communities, and their correlations were evaluated for triticale silages, as affected by Lactiplantibacillus plantarum (LP) inoculation at the heading, flowering, filling, milk-ripening, and wax-ripening stages. (3) Results: The results indicate that the filling and milk-ripening stages without LP inoculation resulted in lower pH and higher lactic acid than other harvest maturity stages ( p < 0.05). Inoculating with LP decreased the pH at each harvest maturity stage, except for the filling stage, and increased the lactic acid concentration at the heading and filling stages ( p < 0.05). The bacterial dynamics indicated that the abundances of Lactiplantebacilli and Monascus of the triticale silages without the LP inoculation were different between the harvest maturity stages ( p < 0.05), and the abundance of Enterobacters was different between the harvest maturity stages in the triticale silage ( p < 0.05). Remarkably, negative correlations were found between the Lactiplantebacillus , Monascus , and pH and positive correlations were found between the Lactiplantebacillus , Monascus , and lactic acid content ( p < 0.05). (4) Conclusions: The filling and milk-ripening stages were the most suitable harvest maturity stages for the triticale silage. Inoculation with LP could enhance the fermentation quality, increase the abundances of beneficial microorganisms, and inhibit harmful microorganisms in triticale silage.