The researchers treated rice straw with ammonium sulphite to see how it affects its nutritional content and degradability. They found that treating the straw with 4% or 8% ammonium sulphite significantly increased the protein and sulfur content, while reducing the fiber content. This treatment also improved the degradability of dry matter and organic matter in the straw, but decreased the degradability of fiber. The 8% treatment had the most significant impact on improving degradability of dry matter and organic matter, while decreasing the degradability of fiber.