Enhancing Effect of Adding Previously Fermented Juice and Sudan Grass on the Quality of Alfalfa Silage

Silage preservation is critical for livestock’s stable forage supply during cold seasons and fostering the recycling of agricultural byproducts. We assessed the effects of adding previously fermented juices (PFJ) and different proportions of <i>Sorghum Sudanense</i> (Piper) Stapf (Sudan grass) on the silage quality of <i>Medicago sativa</i> L. (alfalfa). A 50% alfalfa and 50% Sudan grass (M50) mixture exhibited superior performance in sensory evaluation and fermentation quality. The addition of PFJ (PFJI group) further enhanced quality, and increasing the proportion of alfalfa improved the nutritional quality. However, PFJI had no significant effect on the degradation rates of these nutritional indicators (<i>p</i> > 0.05). As alfalfa proportion increased, the disappearance rates of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber in silage increased. Principal component, correlation, and membership function analyses revealed that treatment with M50 without PFJ (PFJ0+M50) had the best effect, followed by treatment with 25% alfalfa and 75% Sudan grass (PFJ0+M25) and 100% alfalfa (PFJ0+M0). Therefore, the mixing ratio of alfalfa and Sudan grass should be maintained between 25% and 50% to optimize the nutritional and fermentation qualities of silage. These findings offer crucial guidance for alfalfa silage preparation, promoting enhanced livestock industry productivity and sustainable agricultural development.