The researchers studied how adding urea and urease sources to rice straw can improve its nutritional value. They ensiled rice straw with different additives at various moisture levels and found that treated straw had higher protein, energy, and digestibility levels compared to untreated straw. The treated straw also had lower fiber and ash content. Adding 5% urea and urease-containing plant sources like soybean seed meal or cowpea seed meal to rice straw and preserving it for at least 4 days under anaerobic conditions at 40% moisture level can enhance its nutritive value.