Effects of Cellulase, <i>Lactobacillus plantarum</i>, and Sucrose on Fermentation Parameters, Chemical Composition, and Bacterial Community of Hybrid <i>Pennisetum</i> Silage

Hybrid <i>Pennisetum</i> (HP) is a perennial herb with a high yield and high quality, which makes it valuable for research as feed for herbivores. In order to make better use of hybrid <i>Pennisetum</i> as feed, this study studied the effects of cellulase (CE), <i>Lactobacillus plantarum</i> (LP), sucrose (SU), and their mixtures on fermentation parameters, chemical composition, and the bacterial community of hybrid <i>Pennisetum</i> silage. The experiment was divided into 7 treatments, silage treatment, and its abbreviation: CON (control group), CE (100 U/g FM cellulase), LP (1 × 10⁶ cfu/g FM <i>Lactobacillus plantarum</i>), SU (1% FM sucrose), CE+LP (100 U/g FM cellulase + 1 × 10⁶ cfu/g FM <i>Lactobacillus plantarum</i>), CE+SU (100 U/g FM cellulase + 1% FM sucrose), and LP+SU (1 × 10⁶ cfu/g FM <i>Lactobacillus plantarum</i> + 1% FM sucrose). The silage bag was opened on the 60th day of ensilage for subsequent determination. The addition of CE and LP increased lactic acid content (<i>p</i> > 0.05). The pH and acetic acid of CE and LP were lower than CON (<i>p</i> < 0.05), and the crude protein content of CE was higher than CON. Cellulase and <i>Lactobacillus plantarum</i> can improve the quality of hybrid <i>Pennisetum</i> silage. Compared with <i>Lactobacillus plantarum</i> and sucrose, cellulase has better nutrition preservation and the ability to inhibit protein hydrolysis. 16S rRNA analysis showed that the dominant phyla were <i>Fimicutes</i> and <i>Proteobacteria</i>, and the dominant genera were <i>Lactobacillus</i> and <i>Weissella</i>. The changes in fermentation parameters and chemical components of hybrid <i>Pennisetum</i> silage caused by cellulase, <i>Lactobacillus plantarum</i>, sucrose, and their mixture may be the result of bacterial community changes.