Effect of different additives on the silage quality of Longdong alfalfa

Biological additives play important roles in improving the activity of bacteria and enzymes during fermentation, thereby improving the digestibility and quality of silage. In this study, the effects of various additives (formic acid, sucrose, EM bacteria, and cellulase) on the silage quality of the alfalfa cultivar Longdong were investigated by using the first crop of alfalfa as the raw material. The results showed that the sensory evaluation scores of alfalfa silages in the four additive treatment groups were higher than that of the silage in the control group. pH values, acetic acid, and ammonia nitrogen/total nitrogen contents of the silages in the four additive groups were significantly lower than those in the control group silage, and lactic acid content was significantly higher in the treatment group silages than that in the control group silage (P<0.05). No butyric acid and propionic acid were detected. The contents of crude protein in the silages of the four additive groups were significantly higher than that in the control group, and the content of acid detergent fiber was significantly lower in all additive group silages than that in the control group silage (P<0.05). The neutral detergent fiber contents of the silages in the sucrose, EM bacteria, and cellulase groups were significantly lower than those of the silages in the formic acid and control groups (P<0.05). There were no significant differences in the crude ash contents of silages among all the groups (P<0.05). The aerobic stability of silages in the four additive groups was significantly higher than that of the silage in the control group (P<0.05). The results suggested that the four additives can improve the sensory quality, fermentation quality, and nutrient composition of silage produced from the alfalfa cultivar Longdong, and prolong its aerobic stability. The effects of the four kinds of additives on the growth of alfalfa were optimized by adding cellulase.