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final reportp Project code: B.PAS.0235 Prepared by: Dean Revell, Phil Vercoe, Mike Bennell, Jason Emms, Steve Hughes, Zoey Durmic, Marta Monjardino, Felicity Byrne, Andrew Kotze, Andrew Toovey, John O’Grady, Peter Jessop, Tim Wiley Date published: 5 December 2008 ISBN: 9781741914450 PUBLISHED BY Meat & Livestock Australia Limited Locked Bag 991 NORTH SYDNEY NSW 2059 . Multi-purpose ‘healthy’ grazing systems using perennial shrubs Meat & Livestock Australia acknowledges the matching funds provided by the Australian Government to support the research and development detailed in this publication. This publication is published by Meat & Livestock Australia Limited ABN 39 081 678 364 (MLA). Care is taken to ensure the accuracy of the information contained in this publication. However MLA cannot accept responsibility for the accuracy or completeness of the information or opinions contained in the publication. You should make your own enquiries before making decisions concerning your interests. Reproduction in whole or in part of this publication is prohibited without prior written consent of MLA. Enrich Multi-purpose ‘healthy’ grazing systems using perennial shrubs Final Report November 2008 Sheep grazing mixed forage shrubs at the Badgingarra experimental site (March 2008) Dean Revell, Phil Vercoe, Mike Bennell, Jason Emms, Steve Hughes, Zoey Durmic, Marta Monjardino, Felicity Byrne, Andrew Kotze, Andrew Toovey, John O’Grady, Peter Jessop, Tim Wiley 1 Overarching statement The dry margins of southern Australia’s dryland agricultural regions are at risk of becoming economically and environmentally unsustainable. Prolonged drought and trends towards ongoing change in rainfall patterns are making landuse dominated by cropping and annual pastures unsustainable. This represents an opportunity for large scale change to livestock industries, where blending feed production from woody and herbaceous perennials with traditional pastures become the preferred productive landuse in the future. Through the Enrich project we have investigated new options for sustainable grazing systems incorporating Australian perennial shrubs. Shrubs can assist with profit (e.g., provision of out-of-season feed, improving animal health & welfare) and natural resource management (e.g., managing salinity, erosion, hostile soils & biodiversity) because of their ability to grow and persist under difficult environmental conditions and their resilience in our challenging environment. Research team Dean Revell CSIRO, Mike Bennell DWLBC, Philip Vercoe UWA Jason Emms, Steve Hughes SARDI Andrew Toovey, Andrew Kotze, John O’Grady CSIRO Zoey Durmic UWA Tim Wiley DAFWA Peter Jessop NSWDPI Felicity Byrne, Marta Monjardino CRC The assistance of others is gratefully acknowledged, including: David Masters, Hayley Norman, Matt Wilmot, Nathan Phillips, Melissa Groves and Di Mayberry – CSIRO. Naomi Zadow - CSIRO & UWA. Fred Provenza – Utah State University Summary of accomplishments of the project team We interviewed 40 producers in four States who have been using shrubs as part of their forage system, and catalogued some of their experiences, ideas and production systems. We have coupled this with whole-farm economic modelling (using the MIDAS model) to test a range of scenarios that impact on the optimal scale and the profitability of using forage shrubs. For example, under a ‘typical’ central wheatbelt mixed farm, the modelling output indicated that about 10% of a farm allocated to perennial shrubs would increase whole-farm profit in the order of 20%. This conclusion held across a range of scenarios, including different commodity prices, but of course depends on the mix of soil types on a farm and the opportunity costs associated with forage shrubs. We have identified over 100 species of shrub with potential for use as part of a forage system. We have 50 species well established at an evaluation site in Monarto, near Murray Bridge, SA (planted in 2006). As from September 2008, we now have this replicated in Condobolin, NSW and Merredin, WA. We have also collaborated with nine regional groups across WA, SA, Victoria and NSW and have 15-20 species planted across a range of environments. We have developed a unique screening approach to assess, as widely as possible, the potential benefits that forage shrubs may provide. This strategy was designed for two reasons. First, to consider a broader set of traits than has previously been considered, because any one species will have limitations – typically productivity, ‘palatability’ or nutritional profile. Second, because the plants have not been through any plant breeding program, there is potential for plant secondary compounds in shrub species to affect (positively or negatively) livestock production. A range of Australian native shrubs have fermentation characterisitcs (gas production, and/or VFA) comparable to a common supplementary fodder, such as oaten chaff. Within these, there were plants that had rumen-modulating properties such as reduced methane production. There were also plants that had more pronounced effect on these properties, but also affected rumen fermentation. We have also identified that there is significant anthelmintic activity in many of the shrub species examined. This suggests that there is potential for some shrubs to provide a degree of activity against worms in grazing systems. The successful use of mixed plant assemblies, including multiple shrub species and herbaceous plants should be underpinned by an understanding of grazing behaviour and the influence of management on diet selection and feed intake. Ultimately, systems will need to be designed and managed over time and space, which must take into account the dynamics between plants, animals and the environment. A grazing research site has been established at Badgingarra, WA, where 7 woody perennial species are on offer to livestock, together with perennial and annual pastures. Sheep maintained weight without supplementary feeding over autumn (when liveweight loss or supplementary feeding would normally be expected) when the shrubs constituted 5-20% of their DM intake (depending on grazing pressure). We have investigated diet selection under different grazing pressures, the influence of animal experiences on selection, and the potential for one of the shrub species to control intestinal parasites. The dynamic between selectivity, amount eaten and production can be manipulated over time using grazing management. 3 Reporting against project deliverables Prospect statements for shrubs including a shortlist, based on the broad screening process, that warrant further investigation in field experiments and targets for domestication/plant improvement Forage shrubs at about 10% of a typical crop-livestock farm boost profit in the order of 20%. This occurs through direct effects of reduced supplementary feeding over summer/autumn, and deferred grazing of annual pastures that allows an increase in annual stocking rates. This finding held across a wide range of scenarios such as grain or livestock commodity prices, soil types and carbon prices, although the absolute farm profit varied as would be expected. The allocation of shrubs to land that is marginal for cropping is the most likely scenario, where the opportunity cost of competing enterprises or technologies is minimal. Additional benefits of shrubs may also occur. Based on interviews with farmers, shrubs are valued for their positive effects on (i) reducing the risk of wind erosion on vulnerable soil types; (ii) reducing the risk of dryland salinity; (iii) increasing confidence in feed supply at a time when a ‘feed gap’ is typically experienced; (iv) reducing labour demands at the break-of- season when cropping activities are in progress and when hand-feeding livestock competes with labour and management; and (v) provision of shade and shelter for livestock. Furthermore, our in vitro screening of plant species for ‘bioactive’ properties suggest that particular species have potential enhance livestock performance by altering rumen fermentation and/or reducing gut parasite burdens. A shortlist of plants warranting further investigation has been developed (Table 1), but we are keen to state that further evaluation of plant performance is required across more than one site (Monarto, SA). This will be possible in the next phase of research with two new research sites now established (at Condobolin, NSW and Merredin, WA), each with about 50 species under evlaution. In addition, we will have 14 sites, each with 15 species, across southern Australia in partnership with a range of regional groups. Eleven sites have been planted and at least three more are planned for planting in 2009. Detailed information on shrub productivity and adaptability to cultivation in the wheat- sheep zone. About 50 species of shrub were successfully propagated and established at the Monarto evaluation site. Productivity of each of these species is quantified in the following Section 2. Risk reduction practices associated with shrub establishment and their profitable use The key issues that will impact on the profitable use of forage shrubs were quantified through bioeconomic modelling. We tested a range of scenarios, including commodity prices, establishment costs, shrub productivity and nutritive value, combinations of land classes (soil types), and carbon pricing. We focussed our work on the central wheatbelt MIDAS model rather than covering multiple regions. This allowed greater depth of scenario testing in the modelling given