Estimates of the Intake and Digestion of Nitrogen by Sheep Grazing a Mediterranean Pasture as It Matures and Senesces

The level of production by sheep that graze a Mediterranean pasture as it matures and senesces depends on diet selection. By estimatin, 0 diet selection under these conditions using 2 methods, we predict that the intake of nitrogen (N) and amount of N apparently digested (ADN) decreases as the pasture matures and senesces, but that it decreases at a slower rate than the decline in pasture N content and digestibility. A consequence of this diet selection is that wool growth did not decline concurrently with pasture quality. There was a lag between the decline in the predicted amount of ADN and the decline in wool growth; wool growth began to decline about 3 weeks after the onset of senescence.