If the pasture is grazed too hard both plant and animal production will be reduced. If the grazing pressure is too light forage use will be low, forage quality may decrease and animal production per acre will be low. The effect grazing has on forage and livestock production depends on the timing and intensity of grazing. Timing of grazing refers to the rest interval allowed the plant between grazings. Intensity of grazing is how much forage stubble or leaf area is left on the plant at the end of the grazing activity.
Lets review what happens in a plant when as it grows after a harvest.
Timing of grazing should allow the plant to restore its energy reserves. If not given enough time before loosing its leaves again the plant will be weakened, production will be lowered, rooting depth will be reduced and in some cases the plant will die. The time required to restore these energy reserves depends on the plant species, the intensity of defoliation, temperature, soil fertility, and soil moisture. Intensity of grazing is part of this plant regrowth problem. If all leaves are removed from the plant at the time of grazing it must rely entirely on root and stem reserves for regrowth.