ABSTRACT
Summary Grazing experiments were conducted to examine the feeding value of various pastures for grazing sheep and, in some cases, as silage. Recently, the use of legumes for improving the growth of weaned lambs during the dry summer and early autumn was investigated at Hamilton, Victoria. Studies in Australia showed that the fleeceweights of weaner sheep grazed on eight pasture mixtures of varying grass species increased as the amount of clover in the pasture increased (r = 0.88**). In a separate study, young sheep grew faster on lucerne-grass pasture than on grass-subterranean clover pasture. Most recently, live-weight gains of 4-month-old lambs grazing legumes during 3 dry months in summer-autumn were 9.5, 9.4, 8.9, and 8.7 kg/head on red clover, giant shaftal clover (T. resupinatum), lucerne, and white clover pasture, respectively, greater than those obtained on perennial ryegrass-subterranean clover pasture (0.4 kg/head) or cocksfoot-subterranean clover pasture (2.2 kg/head). In studies made in Ireland, store lambs offered unchopped wilted silage for 8 weeks had higher intakes of grass-red clover silage than of grass silage; corresponding carcass gains were 0.35 and 0.16 kg/week. Carcass gain/unit of digestible dry matter (DM) consumed was higher for grass-red clover silage than for grass silage. Mean retention time of DM in the reticulo-rumen was 19% shorter with the grass-clover silage. Superior animal performance on legume-dominant pasture occurred, sometimes despite a higher DM production from grass-dominant pasture. Producers should aim to provide at least 30% legume in sheep pastures in southeastern Australia, especially in the dry summer when the feeding value of grass falls rapidly. Plant improvement should aim at providing perennial legumes suitable for all main soil and climate environments.
