Abstract This study evaluated wool quality and lamb production from four management systems grazing a perennial pasture but using different combinations of lambing time, ram breed, and percentage of summer-active pasture species, between 2006 and 2010. All systems were stocked at a similar mid-winter dry sheep equivalent per hectare (8, 10.2, 13, 11.2 and 11.2 in 2006 to 2010, respectively). The weight, condition score, C fat and eye muscle depth at weaning of both Merino and crossbred lambs were always higher (P<0.05) for lambs born in July compared with those born in September. Similarly, the sale weight of lambs born in July was always higher (P<0.05) than for lambs born in September, partly because these lambs were usually retained for longer before sale. When lambs were born in September, sheep systems which carried larger numbers of ewes/ha at the same mid-winter stocking rate produced similar sale weights of lambs as those with fewer ewes, except where systems with less lambs/ha enabled lambs to be retained for longer in favourable seasons. A larger proportion of lucerne area (40% cf. 20%) only increased lamb sale weights in favourable seasons. Clean fleece weights per ewe and staple strength were similar between systems in most years (2008 to 2010), although mean fibre diameter was lower (P<0.05) in the HL and LL systems. The results indicate that choice of lambing time, ram breed and the flexibility to alter lamb sale date with seasonal conditions, will have a larger impact on the performance of individuals than ewe numbers/ha, where systems are grazed at the same mid-winter stocking rate.