Definition of Forage Quality

Forage quality decreases as plants grow older. This occurs because, as plants get larger and more stemmy, a greater percentage of nutrients and dry matter is tied up in non-digestible forms (such as lignin). Greater amounts of non-digestible fiber result in lower quality forage with decreased amounts of total digestible nutrients (TDN).

A good manager needs to balance pasture quality with pasture yields. The best time to graze is immediately following the most rapid growth but before flowering and seeding. At this stage, sufficient carbohydrate reserves have been built up to allow for rapid regrowth; in addition, both yield and quality are high. If grazing occurs before this stage when the forage has not had time to rebuild its carbohydrate reserves, yield will be low, the next regrowth may be slow and reduced, and winter survival may be decreased. One of the cornerstones of successful grazing system is having rest periods long enough to allow for rapid forage regrowth.