Lactic Acid Bacteria and Cellulase Improve the Fermentation Characteristics, Aerobic Stability and Rumen Degradation of Mixed Silage Prepared with Amaranth and Rice Straw

Abstract

The aim of this experiment is to investigate the effects of lactic acid bacteria and cellulase on the fermentation quality, chemical composition, aerobic stability and ruminal degradation characteristics of mixed silage prepared with amaranth and rice straw. Lactic acid bacteria and cellulase were used as silage additives, and the four treatments were as follows: control group (CON, no additive), lactic acid bacteria group (LAB, additive amount was 5 mg/kg fresh matter), cellulase group (CEL, 2 mg/kg) and lactic acid bacteria and cellulase group (LBC, additive amount was the same as in the individual treatments). All treatments were ensiled for 60 days. The dry-matter, crude-protein, neutral-detergent-fiber and acid-detergent-fiber ruminal degradability of silage were analyzed utilizing the nylon bag method. Compared with the CON group, the inoculation of lactic acid bacteria and cellulase individually promoted the fermentation of mixed silage to a certain degree. The combined inoculation of mixed silage significantly increased (p < 0.05) the concentrations of lactic acid and dry matter, while it reduced (p < 0.05) the pH and ammonia nitrogen/total nitrogen, harmful microorganism counts and contents of acetic acid, neutral detergent fiber and acid detergent fiber. In addition, the aerobic stability time of the LBC group was lower (p < 0.05) than that of the other groups. The ruminal degradation rate of dry matter, crude protein, neutral detergent fiber and acid detergent fiber in the LBC group was significantly increased (p < 0.05) compared to the CON group. Overall, the addition of the additives mentioned earlier improved the quality of mixed silage composed of amaranth and rice straw, and the best results were obtained by combining the inoculation of lactic acid bacteria and cellulase.