This research aims to increase the sustainability of feed availability by creating feed independence. Corn is the primary energy source for livestock, but when the price of corn rises and its supply declines, it becomes essential to find alternative ingredients to use in animal feed. This study explores the use of cassava (tapioca by-products) and tofu dregs as substitutes for corn through fermentation technology using Neurospora sp. This produces alternative feed ingredients with nutrient levels that are in balance with corn. To improve the quality of the cassava-tofu dreg mixture, this study used red oncom mushrooms enriched with Na-glutamate during the fermentation process. The research used a completely randomized factorial design, where two factors were considered: the addition level of Na-glutamate (0%, 0.5%, 1%, and 1.5%), and the addition level of red oncom mushrooms (0%, 5%, 10%, and 15%). Each treatment was repeated twice, followed by an orthogonal polynomial test. The variables observed were nutrient contents, including moisture, crude fat, crude protein, crude fiber, NFE, calcium and phosphor, and anti-nutritional phytic acid. The results showed that the fermentation process using red oncom mushrooms enriched with Na-glutamate improved the nutritional level of the cassava-tofu dreg mixture. Although the NFE content decreased, the crude fiber content increased, and the amounts of calcium, phosphorus, and protein significantly increased (P < 0.05). Furthermore, fermentation reduced the phytic acid content to 90.83% at 1.5% Na-glutamate and 15% red oncom mushroom level. In conclusion, this research demonstrates that the quality of cassava-tofu dreg mixture can be enhanced through fermentation using red oncom mushrooms enriched with Na-glutamate. This approach can increase the sustainability of feed availability and reduce the dependence on corn as the primary energy source for livestock.