Forage quality is commonly defined as the nutrient concentration and digestibility of forages. It is important to emphasize that in the technical literature, forage quality is defined by forage nutritive value and intake. The nutrient concentration of forages directly impacts individual animal performance (e.g., growth, milk production), while the total amount of forage produced determines the animal production per area.
Read more: https://blogs.clemson.edu/livestock/understanding-forage-quality-and-its-importance-for-livestock-based-systems/