Not about grass, but providing a context for possible grazing land improvement.
Creating shelter protects livestock and allows earlier lambing and reduced feed costs through increased mineral nutrition from the leaves. The animals like the habitat the trees provide and self medicate from the hedgerows. Some trees can be harvested for fodder and bedding. Secondary longer term uses in harvested timber for fence post replacement, building purposes and firewood.
Environmentally contributing to carbon capture and flood water absorption - this video focuses on upland areas where this function is even more critical.