The objective of this study was to assess the effect of Italian ryegrass (Lolium multiflorum Lam.) sward height on lamb performance. The experiment was carried out at the Research Station of UFRGS, Eldorado do Sul, Brazil. Yearling no-castrated male lambs were assessed in terms of individual animal performance and gain per hectare. The experiment was carried out in a randomised block design with three replications of four treatments: 5, 10, 15 and 20 cm of sward surface height (SSH), which were maintained using continuous variable stocking, and monitored by a sward stick. Samples of 0.25 m2 were cut to ground level to estimate herbage and leaf lamina mass. Live weight gain per area and per animal increased in a quadratic pattern. The best animal production was found in a sward of approximately 15 cm high
