Grazing by sheep and the distribution of species through the canopy of a red clover‐perennial ryegrass sward

A trial was carried out to investigate whether or not sheep grazing at stocking rates of 22 (low) and 44 (high) ha −1 select red clover from a red clover‐perennial ryegrass sward, The distribution of botanical and morphological components was assessed in consecutive 5‐cm layers through the canopy inside and outside exclosure cages moved every 2 weeks for 6 weeks. The difference between inside and outside cages for a given layer was an indication of the amount of each component consumed from that position in the sward, and the corresponding difference for clover content was considered an indication of selection. Evidence of selection was observed over the third and fourth weeks of grazing, especially in the high stocking rate treatment. Laminae of red clover were selected in preference to other plant parts and were grazed throughout the depth of the canopy in contrast to grass. The basal layer at the high stocking rate during weeks 5 and 6 was not grazed suggesting that the crown of red clover may be protected from severe overgrazing by accumulation of dead matter. It was concluded that the low herbage density of red clover‐grass swards allowed the occurrence of selection which was most pronounced when the sward was being grazed down relatively quickly.