There was no consistent pattern in the ratings by individuals but, in fact, the bale judged best on the basis of appearance had the lowest RFV of the four. Clearly, objective forage analysis is required. Van Soest Fiber Analysis System separates feeds into distinct fractions that relate to their nutritive value. Forage laboratories analyze samples for NDF, ADF, and total nitrogen. The relative importance of each of these factors, along with some exceptions to the ranking, are described below.
Maturity is the most important factor affecting forage quality.
As plant cell wall content increases, indigestible lignin accumulates. In fact, forage plant maturity changes so rapidly that it is possible to measure significant declines in forage quality every two or three days. Differences in forage quality between grasses and legumes can be very large. The protein content of legumes is typically much higher than that of grasses, and legume fiber tends to digest faster than grass fiber, allowing the ruminant to eat more of the legume. Improper harvest techniques can seriously reduce forage quality, primarily through the loss of leaves.