Legume production paddocks to improve beef enterprise productivity and grassland management

Abstract

Weaner or steer production of tropical cattle breeds for feeder or live export markets is the dominant primary industry in the seasonally-dry zone of northern Australia. Uncleared savannah woodlands and natural grasslands are key feed resources, with smaller cleared areas used for pasture development or cropping. Extended dryseasons, soils of mostly low to moderate fertility and the maturation characteristics of native grasses limit animal growth and market options for producers. Land condition decline and the associated increase in early maturing introduced grasses (Bothriochloa pertusa and Themeda quadrivalvis) are emerging issues for beef producers. Recent research in north Queensland by the Queensland Government, with support from the Australian Government and Meat and Livestock Australia, has focussed on the development and promotion of ‘production paddocks’ using deep-rooted and productive legumes (Clitoria, Desmanthus, Macroptilium, Stylosanthes). These relatively intensively-managed paddocks target the nutrition of weaners and steers during the early to mid dry season to (1) enable earlier sale or higher sale weights of cattle, and (2) encourage sustainable grazing practices through spelling other areas on the property enabled by improved animal productivity. Small-plot studies of grass x legume combinations on commercial beef properties resulted in pasture yields 2-3 times those achieved on native pastures on fertile and infertile soils. Critically, the legume component contributed leaf with high feed value (15- 20% crude protein and 8-10 MJ/kg metabolisable energy) when companion grasses had low feed value. The high quality of the dry season feed provided by legumes was confirmed using faecal sample testing.