Ammoniating wheat straw with urea increases its protein content and digestibility for sheep. The treated straw had more soluble protein and higher nitrogen intake and retention in sheep compared to untreated straw. However, lignin digestibility decreased after treatment. Sheep ate similar amounts of both treated and untreated straw, and their nutrient digestibility was not significantly different. Overall, ammoniating wheat straw can improve its nutritional value for sheep by increasing protein content and digestibility.