As forage plants mature, energy availability and protein content decrease. Forage intake decreases as nutrient availability or digestibility decreases. Ideally, the livestock manager would like the forage plants to have a high leaf area compared to stems. Leaves are more digestible than stems. Livestock will selectively graze leaves and petioles, before grazing stems.
Leaves also decline more slowly in digestibility than stems.
In a rotational grazing system, regrowth will be more leafy and thus maintain higher digestibility longer. The Animals Producers can monitor the effectiveness of the nutrition program in the longterm by herd performance records. Dairymen can quite easily assess changes in forage quality by reading the dipstick in the bulk tank. This system also had an advantage compared to body weight in that scales or corrals are not needed for body condition evaluation. Body condition scoring tools are available at your County Extension Office.