In general, legumes will be of higher quality than grasses. As a crop matures, its leaf to stem ratio declines and so does quality. In general the presence of pests will reduce the quality of the forage. Rain-damaged hay will be less valuable than non-damaged hay. Too high a moisture can lead to mold formation in a hay crop and too low a moisture results in leaf shatter and, thus, a poorer quality crop. With silage, a long chop doesn’t compact well and too short of a chop reduces the “effective fiber” for the consuming animal. Fertility level impacts the amount of minerals in the forage.