The purpose of this study was to determine pasture attributes, liveweight gain and stocking rate from a mixed pasture grazed by lambs recieving different supplementation levels. There were four treatments: in two, lambs grazed at 4 or 8% herbage allowance, no supplement; in the other two, lambs grazed at 4% herbage allowance plus a concentrate to cover 25 and 30 or 50 and 60% of estimated daily needs of metabolizable energy and crude protein. Pasture was of perennial and annual ryegrass, orchard grass and red clover. Pre and postgrazing forage mass, crude protein and dead material were not different (P\u3e.05) among treatments. The highest live-weight gain was 145g/lamb/day found in lambs recieving concentrate. Stocking rate was 56 lambs/ha in 4% allowance-treatments and 29 lambs/ha with 8% allowance. Supplementation did not influence pasture attributes while giving higher live-weight gain in lambs. Doubling herbage allowance gave lower lamb performance than offering a concentrate and decreased stocking rate
