The purpose of the current research was to evaluate the influence of lactic acid bacteria and cellulase supplementation on the chemical composition, fermentation parameters, aerobic stability, microbial count, and in vitro nutrients digestibility of silage prepared with Pennisetum giganteum and rice straw. This study consisted of four treatments: a control group with no additive supplementation (CON), a lactic acid bacteria supplementation group (LAB), a cellulase supplementation group (CEL), and a combined supplementation group (LAC). After ensiling for 60 d, the chemical composition, fermentation parameters, microbial count, and aerobic stability were determined. Additionally, ruminal fermentation characteristics were evaluated by an in vitro incubation technique. Compared with CON silage, the quality of LAB and CEL silages was enhanced to a certain degree. Combined supplementation with lactic acid bacteria and cellulase in mixed silage of Pennisetum giganteum and rice straw noticeably increased (p < 0.05) the dry matter, crude protein, and lactic acid contents, whereas it reduced (p < 0.05) the pH and ammonia nitrogen/total nitrogen as well as the neutral detergent fiber and acid detergent fiber concentrations. The lactic acid bacteria count in LAC silage was higher (p < 0.05) than that of CON silage, whereas an opposite trend of yeast, aerobic bacteria, and mold was observed between the two groups. The aerobic stability time, in vitro crude protein, and neutral detergent fiber digestibility in LAC silage were significantly increased (p < 0.05) compared with those in CON silage. Moreover, the in vitro ruminal ammonia nitrogen content was reduced (p < 0.05), and the microbial protein and propionic acid concentrations were increased (p < 0.05) in silage after combined inoculation with additives. Taken together, the quality of Pennisetum giganteum and rice straw mixed silage can be improved by inoculation with lactic acid bacteria and cellulase, and combined supplementation shows the greatest improvement in silage quality.

This research evaluated the influence of lactic acid bacteria and cellulase, individually or in combination, on the quality of mixed amaranth and sweet potato vine silages. The experiment included four groups: control group with no additives addition (CG), added cellulase group (AS1), added lactic acid bacteria group (AS2) and combined supplementation group (AS3), with five replicates per group. The ensiling period lasted for 60 days. Parameters of silage, including chemical components, fermentation profile, aerobic stability, and in vitro nutrient digestibility, were determined. The results revealed that the quality of amaranth and sweet potato vine mixed silage was improved to a certain degree after addition of two additives individually. Combining these additives observably increased (p < 0.05) the lactic acid and crude protein contents and decreased the pH, ratio of ammonia nitrogen to total nitrogen and neutral detergent fiber content of mixed silage. Compared with the CG and AS1 groups, the number of lactic acid bacteria in the AS3 group increased significantly (p < 0.05), while aerobic bacteria and mold counts showed the opposite tendency. Also, the in vitro dry matter, crude protein and neutral detergent fiber digestibility of the AS3 group were higher (p < 0.05) than those of the CG group. Combined inoculation observably reduced (p < 0.05) the ammonia nitrogen concentration and increased (p < 0.05) the propionic and butyric acid concentrations of mixed silage under in vitro incubation. In summary, the inoculation of lactic acid bacteria and cellulase can enhance the fermentation profile and nutritional values of mixed silage made from amaranth and sweet potato vine, and the best improvement effects are obtained by the combined utilization of the two additives.

This experiment evaluated the application effects of the dietary substitution of maize silage with mixed silage prepared with Pennisetum giganteum and rice straw on fattening lambs. Forty-eight male Hu lambs with similar body weights and ages were randomly divided into four groups. The maize silage in the diet was replaced with Pennisetum giganteum and rice straw mixed silage in proportions of 0 (CON), 25% (PR1), 50% (PR2) and 75% (PR3). The average daily gain of the PR3 group was lower (p < 0.05) than that of the other groups. The highest substitution level increased (p < 0.05) ruminal ammonia nitrogen concentration and acetate-to-propionate ratio in lambs compared with the CON and PR1 groups. Moreover, dry matter and neutral detergent fiber digestibility in PR3 lambs were lower (p < 0.05) than in PR1 lambs. Compared with the CON group, the concentrations of serum catalase and total antioxidant capacity were increased (p < 0.05) in the PR2 and PR3 groups. Overall, the dietary substitution of maize silage with Pennisetum giganteum and rice straw mixed silage at a 50% level did not show a negative influence on growth performance of fattening lambs but displayed positive effects on their fiber digestibility and antioxidative capacity.